Research ArticlePrevalence Risk Factors and Antibiogram of BacteriaIsolated from Milk of Goats with Subclinical Mastitis inThika East Subcounty Kenya

PreciousMahlangu1 NaomiMaina 12 and John Kagira 3

1Department of Molecular Biology and Biotechnology Pan-African University Institute of Basic Sciences Technology and InnovationPO Box 62000-00200 Nairobi Kenya2Department of Biochemistry Jomo Kenyatta University of Agriculture and Technology PO Box 62000-00200 Nairobi Kenya3Department of Animal Sciences Jomo Kenyatta University of Agriculture and Technology PO Box 62000-00200 Nairobi Kenya

Correspondence should be addressed to John Kagira jkagiragmailcom

Received 29 August 2018 Revised 17 October 2018 Accepted 30 October 2018 Published 11 November 2018

Academic Editor Nora Mestorino

Copyright copy 2018 Precious Mahlangu et al This is an open access article distributed under the Creative Commons AttributionLicense which permits unrestricted use distribution and reproduction in any medium provided the original work is properlycited

A cross-sectional study was carried out to determine the prevalence and risk factors of subclinical mastitis in dairy goats in ThikaEast Subcounty Kenya Further the bacterial pathogens and their antibiogram were investigated Farm level data on risk factorswere obtained from 41 farmers using questionnaires Milk was obtained from 110 lactating dairy goats and tested for submastitisusing California Mastitis Test (CMT) The prevalence of subclinical mastitis at goat level was estimated to be at 509 usingCMT out of which 865 yielded bacteria on culture The significant risk factors associated with the occurrence of subclinicalmastitis were cleaning schedule (p=0022 OD=1047) and parity of the goat (p=0048 OD=137) Higher prevalence of subclinicalmastitis was observed for goats residing in houses cleaned at least once a fortnight Does in the first parity were least affected 169bacterial isolates were obtained from culture of which 52 isolates from major classes of isolated bacteria were tested for antibioticsensitivity to six antibiotics Fourteen different bacteria were isolated and identified from the milk samples Coagulase-negativeStaphylococci (207) Serratia spp (195)Citrobacter spp (16)Klebsiella spp (11) Staphylococcus aureus (107)Enterobacterspp (65) Escherichia coli (59) Proteus spp (3) Corynebacterium spp (18) Morganella spp (18) Streptococcus spp(12) Providencia spp (06)Micrococcus spp (06) and Staphylococcus intermedius (06) were isolated and identified fromthe samples All the isolates were resistant to Penicillin G while 98 of the isolates were sensitive to Streptomycin In conclusionthe study showed that a large proportion of goats were affected by subclinical mastitis with the main bacteria being Staphylococcispp and coliforms and that most of the tested antibiotics can be used in the treatment of mastitis Farmers need to be trained onimproved control of mastitis through adoption of good dairy husbandry and milking practices

1 Introduction

Dairy goat farmers suffer severe economic losses due to intra-mammary infections [1] The losses due to mastitis emanatefrom poor milk quality reduced milk yield increased expen-diture on treatment milk discard after treatment and some-times death due to the disease itself or through culling ofaffected livestock [2ndash4] Goat milk and its products have amajor significance in human nutrition and have been usedextensively in feeding starving and malnourished peoplein developing countries [5] Consequently any factor that

adversely affects the quantity and quality of milk from thegoat is of great economic interest [6] Although in recentyears dairy goat farming has gained interest in central partsof Kenya challenges such as occurrence of mastitis limitits adoption Diseases such as mastitis have been shown tohinder the growth of dairy goat production systems [7]

Mastitis is the inflammation of the mammary glandincluding not only intramammary tissues but also relatedanatomical structures such as nipples mammary areolas andmilk ducts [8] It is characterized by changes in the physicalchemical pathological and bacteriological characteristics

HindawiJournal of Veterinary MedicineVolume 2018 Article ID 3801479 8 pageshttpsdoiorg10115520183801479

2 Journal of Veterinary Medicine

of the udder or milk [8ndash10] Mastitis leads to milk yieldreduction and affects the sensory quality and fatty acid profileof the by-products like cheese [11] Mastitis manifests eitheras subclinical inwhich therersquos no visible symptom or clinicalin which visible symptoms do occur varying from mild tosevere [2] Subclinical mastitis is also significantly associatedwith a great increase of leucocytic cells in the milk whichare used as indicators of the condition and milk quality [7]As subclinical mastitis is less obvious and detectable only bymeasures of milkrsquos cellular content it is 15-40 times moreprevalent than the clinical form [12]This is a concern amongproducers and veterinarians as there are no visible signs of thedisease which can eventually develop into the chronic clinicalform of mastitis Subclinical mastitis in goats is mainly ofbacterial origin [13]Mastitis is generally associatedwith poorhygienic practices and is caused by the bruising of mammarytissue or teats from traumas nursing fly bites or otherwounds to the skin which provide an important barrier toinfection [14]

Subclinical mastitis can be recognized indirectly by sev-eral diagnosticmethods including theCaliforniaMastitis Test(CMT) the modified white side test Somatic Cell Count(SCC) pH milk electrical conductivity tests and catalasetests The SCC and CMT are the most common tests usedto diagnose mastitis in dairy goats [15] The CMT has beenfound to be more perfect efficient and reliable than otherfield and chemical tests for diagnosis of subclinical mastitis[12 16ndash18] The CMT is based on the reaction between theCMT reagent and the DNA genetic material of the somaticcells A higher concentration in somatic cells leads to ahigher CMT score CMT scores are directly related to averagesomatic cell counts [19]

A report on the interpretation of CMT scores on goatmilk has been made [20] It was reported that in generalmilk from noninfected glands will yield a negative (0) traceor 1 reaction Scores of 2or 3 are indicative of mastitisSomatic cell counts in excess of 1500000ml are suggestiveof intramammary infection [12]

Some authors have evaluated the sensitivity and speci-ficity of CMT as a rapid field-based test in the field InAlgeria the specificity and sensitivity of the CMTwere foundto be 96 and 99 respectively [18] Another study [21] alsoconcluded thatCMTcanbe used as a rapid test as it was foundto be highly sensitive in the study

Correct diagnosis and identification of the etiologicalagent causing mastitis are essential in determining the treat-ment strategies [22] Antibiotics have been used routinelyto treat mastitis [23] therefore an increase in the incidenceof mastitis warrants an increase in the use of antibiotics[22] This increases the risk of antibiotic resistance There istherefore a need to properly identify the causative pathogendetermine its antibiotic susceptibility profile assess the mostappropriate antibiotic to use and administer sufficient treat-ment to completely get rid of the pathogen [23]

In this study the prevalence risk factors and bacterialpathogens causing subclinical mastitis in dairy goats inThikaEast Subcounty Kenya were isolated and their susceptibilityto antibiotics was determined

2 Materials and Methods

21 Description of Study Area The study was carried outin Thika East Subcounty of Kiambu County Kenya Thesubcounty is located in the central part of the country aboutforty kilometres from Nairobi city It lies between latitudes1∘S and 11015840 south of the Equator and longitudes 37∘rsquo and 51015840east Rainfall is bimodal and ranges from 500 mm to 1300mm while the average temperature is 187∘C According toLivestock Production Officers in the study area farmers havetaken up the dairy goat farming although no proper censushas been undertaken (personal communication Thika EastSubcounty Veterinary Officer)

22 Study Design Sample Size Determination and Adminis-tration of Questionnaires A descriptive cross-sectional studydesign was used The sample size of 110 lactating dairygoats was calculated using an adjusted formula for smallpopulations [24]The sampling unit of interest was individualsmallholder dairy goat farms whose goat flocks size rangedbetween 1 and 10Only farmswith lactating goats were visitedSince there was no formal list of dairy goat farmers in thestudy area the snowball technique and sampling to redun-dancy method were used as a sampling strategy to locate thefarmers The initial farmers were identified with the help ofthe local extension officers Thereafter these farmers helpedin further identification of other farmers with lactating goatsuntil all the farmers in subcounty were covered Using thisstrategy a total of 41 farmers were identified from which thelactating goats were identified At all the farms details of thelactating goats including age breed parity and lactation stagewere obtained from the farmer through administration of aquestionnaire

23 Milk Sampling and California Mastitis Test Milk sam-ples were collected aseptically [18] Briefly the does wererestrained and thereafter the teats were scrubbed with cottonwool saturated with 70 ethanol The teats were dried usinga towel and the first three streams of milk were discarded3 ml of milk from separate teats was milked into a CMTpaddle and an equal amount of a commercial CMT reagent(Immucell RP USA) was added to the paddle The CMTpaddle was rotated in a circular motion to thoroughly mixthe contents Gel formation was observed within 20 secondsThe results were read on a score of 0-3 A score of 0 traceand 1 was considered negative while a score of 2 and 3 wasconsidered positive From the CMT positive animals 5 ml ofmilk was collected into sterile universal bottles The sampleswere placed in cool boxes with ice packs and transportedto Microbiology Laboratory Jomo Kenyatta University ofAgriculture and Technology within 24 hours

24 Culture and Identification of Bacteria The culture andidentification were carried out using standard methods [25]Sheep blood agar (Himedia India) and MacConkey agar(Oxoid UK) were prepared according to manufacturerrsquosinstructions The agar was left to set and stored in a refriger-ator until use 100 120583l of the milk sample was inoculated ontoboth sheep blood agar and MacConkey agar The milk was

Journal of Veterinary Medicine 3

allowed to dry and streaking was done using a sterile loopThe plates were incubated at 37∘C for 24-48 hours

The morphology of the bacterial colonies obtained waschecked for the colony size shape texture and colourHaemolysis of the red blood cells in the sheep blood agar wasalso checked for by identification of the changes in the mediaaround and under the colonies After 48 hours plates with nogrowthwere recorded as no growth Plateswithmixed growthwere subcultured to obtain pure colonies

The gram-staining technique was used to differentiatebetween Gram-positive and Gram-negative bacteria [26] andalso to note the microscopic shape of the bacteria Biochemi-cal tests were used to further identify bacteria according tostandard methods [25] Identification of bacteria was pri-marily made on the basis of colony morphology haemolyticcharacteristics and gram-stain reaction and catalase testThe gram stain was used to differentiate between Gram-positive and Gram-negative isolates For the Gram-positiverods the catalase and mannitol test were further used foridentification of Corynebacterium The catalase tests using3 hydrogen peroxide were done to differentiate Streptococ-cus from Staphylococcus andMicrococcus Staphylococcus andMicrococcus species were identified based on their growthcharacteristics on Mannitol Salt Agar (Himedia India) slidecoagulase test using rabbit plasma catalase and oxidasetests (Himedia oxidase disks) Staphylococcus aureus was dif-ferentiated from coagulase-negative Staphylococci using theslide coagulase test S aureus isolates were further identifiedusing Polymerase Chain Reaction using S aureus-specific16S rRNA primers

The oxidase test was carried out on all Gram-negativeisolates to identify the family Enterobacteriaceae Oxidase-negative isolates were subcultured on MacConkey agar(Oxoid UK) to determine lactose fermentation Thereafterthe Triple Sugar Iron (Oxoid UK) (TSI) test citrate (SimmonCitrate Agar Himedia India) motility (Simmedia-HimediaIndia) indole (Tryptone broth Himedia India) Methyl RedVoges-Proskauer (Himedia India) urease (Urea broth baseHimedia India) mannitol and catalase tests were used foridentification of Gram-negative bacteria Dichotomous keys[25 27] were used for identification using results of haemoly-sis colonymorphology gram staining and biochemical tests

25 Antibiotic Susceptibility Testing Antibiotic susceptibilitytest was performed using the disc diffusion method [28]Pure cultures of isolates from the seven major isolatedbacteria were randomly selected (n=52) and standardized to05 McFarlandrsquos standard Mueller Hinton Agar (Himedia)plates were inoculated with standardized inoculums of thetest organism Six locally available and commonly usedantibiotics for treatment of mastitis in Kenya were selectedfor antibiotic susceptibility testing in the studyThe antibioticdiscs used were Penicillin G (10 IU) Gentamycin (10120583g)Streptomycin (10 120583g) Tetracycline (30 120583g) Chloramphenicol(30120583g) andNorfloxacin (10 120583g)The discs were placed on theagar surface The plates were incubated at 35∘C for 18 hoursThemeasurement of the inhibition zone was done and resultswere compared [28] Results were recorded as resistant orsusceptible to specific antibiotics

26 Statistical Analysis The coded data was entered intoMS Excel (Microsoft USA) spreadsheet and exported toSPSS (Microsoft USA) and R for data analysis Descriptivestatistics were presented as tables A chi square test was usedto evaluate associations between risk factors and mastitisinfection (plt005) Logistic regression was used to testindividual risk factors and their strength of association inmastitis infection The odds ratio was used to determine thestrength of associations identified in the logistic regressionprocedure

3 Results

31 Characteristics of Farms and Sampled Goats A total of41 farms were sampled from the study area Most of thefarms were a quarter acre (805) and the largest acreage wasone and a half acres The majority of goat houses (756)were raised timbers while others were earthen Zero grazing(854)was mostly practiced though some farmers practicedopen grazing and tethering Almost all the farmers (976)kept poultry Most of the farmers (634) were not awareof occurrence of mastitis in their flocks The frequency ofmilking the does ranged from once (805) to twice (195)a day All the farmers indicated that they did pre- andpostmilking teat cleaning procedures In most of the farms(951) the milk was consumed at home

32 Prevalence of Subclinical Mastitis and Identification ofthe Bacteria Using the California Mastitis Test (CMT) theprevalence of subclinical mastitis at doe and udder level wasfound to be 509 (56110) and 405 (89220) respectivelyOut of the samples which were positive by CMT 865(7789) gave a positive bacterial culture and 169 isolates ofbacteria were obtained from the cultures

The results of the bacteria isolated and their frequencyare given in Table 1 In descending order the isolatedbacteria were coagulase-negative Staphylococci Serratia sppCitrobacter sppKlebsiella spp Staphylococcus aureus Enter-obacter spp E coli Proteus sppCorynebacterium spp Mor-ganella spp Streptococcus spp Providencia sppMicrococcusspp and Staphylococcus intermedius

33 Relationship between Prevalence and Risk Factors Theresults of theCMTwere used to evaluate relationship betweenprevalence and risk factors In terms of doe breeds thehighest prevalence of subclinical mastitis was found inGerman alpine (667) followed by crosses and the leastaffected breed was the Kenyan alpine However there wasno significant (p=03934 OD=1059) difference between thebreeds and the prevalence of subclinical mastitis [Table 2]The highest percentage of goats with subclinical mastitis wasfound in goats aged 4 years and above (57) However therewas no significant [p=02347 OD=179] difference betweenthe prevalence of subclinical mastitis and the age of the doe[Table 2]

The highest prevalence (78) of subclinical mastitis wasfound in the does in the early lactation stage However therewas no significant difference (p=04251 OD=0803) between

4 Journal of Veterinary Medicine

Table 1 Bacteria isolated from dairy goats in Thika East Subcounty Kenya

Bacterial species Number of isolates Percentage ()Coagulase-negative Staphylococci 35 2070Serratia spp 33 1953Citrobacter spp 27 1598Klebsiella spp 19 1124Staphylococcus aureus 18 1065Enterobacter spp 11 651E coli 10 592Proteus spp 5 296Corynebacterium spp 3 178Morganella spp 3 178Streptococcus spp 2 118Providencia spp 1 059Micrococcus spp 1 059Staphylococcus intermedius 1 059Total 169 100

Table 2 Effect of breed age and lactation stage on prevalence of subclinical mastitis in dairy goats inThika East Subcounty as identified byCMT

Risk factor Proportion positive Prevalence of mastitis ()BreedGerman alpine 69 667Crosses 2646 565Toggenburg 1020 50Others 510 50Kenyan alpine 925 36Age (yrs)1 23 672 1839 463 1938 504 and above 1730 57Lactation stageEarly 1418 78Mid 1639 41Late 2653 49Early 1 day-3 months mid 3-6 months and late gt6 months

the occurrence of mastitis and the different lactation stages[Table 2]

The lowest prevalence of subclinical mastitis was found ingoats in the first parity [Table 3] and a significant (p=00477OD=1370) increase of prevalence was noted as the parityincreased

The highest prevalence of subclinical mastitis was foundin lactating does whose houses were cleaned fortnightly and asignificant [p=0022 OD=1047] increase was noted with lesscleaning [Table 3]

34 Antibiotic Susceptibility Testing Results S aureus wasmost sensitive to Gentamycin (100) Chloramphenicol(100) and Streptomycin (100) followed by Tetracycline(75) and Norfloxacin (75) All (100) coagulase-negative

Staphylococci (CNS) were sensitive to Gentamycin Chloram-phenicol and Norfloxacin Of the CNS isolates 90 weresensitive to Streptomycin and 80 toTetracycline All (100)the isolates tested were resistant to Penicillin G [Table 4]

Overall the isolates tested were most sensitive to Strep-tomycin (98) and least sensitive to Tetracycline (63)Of the tested isolates 31 of the isolates were resistant toTetracycline and 21 to Chloramphenicol

Multidrug resistance was found in 2 S aureus isolates(resistant to Penicillin G Tetracycline and Norfloxacin)3 Citrobacter isolates (resistant to Penicillin G Chloram-phenicol and Tetracycline) 1 Serratia isolate (resistant toPenicillin G Chloramphenicol and Tetracycline) and 2Ecoli isolates (resistant to Penicillin G Tetracycline andChloramphenicol)

Journal of Veterinary Medicine 5

Table 3 Effect of parity and cleaning schedule on prevalenceof subclinical mastitis in dairy goats in Thika East Subcounty asidentified by CMT

Risk factor Number of positive does Proportion ()Parity1 15 432 22 483 7 584 and above 12 71Cleaning scheduleWeekly 30 46Fortnightly 19 73Daily 4 33Irregular 3 42

4 Discussion

The findings of this work on the prevalence of subclinicalmastitis were higher than those reported in Kenya [29]Greece [6] Spain [17] Pakistan [30] and India [31] Theresults were comparable to the study in Bulgaria [32] whichfound prevalence of 442 The results were lower thanthose reported elsewhere in Kenya and Tanzania [7 33]which found prevalence of 57 and 77 respectively Thedifferences in prevalence of mastitis in various studies havebeen attributed to the differences in host and managementfactors which influence intramammary infection of goats [9]

Mastitis has a multifactorial nature with a clear inter-action between host agent and environment [24] Thedifferences in prevalence of studies undertaken in Kenya[7 34] could be due to differences in farm management andclimate of the various regions Further the high incidenceof subclinical mastitis may be attributed to poor hygienelack of standard milking procedures lack of proper pre- andpostudder washing and nonusage of teat dips [7]

The overall prevalence of subclinical mastitis at udderlevel was lower than that at the doe level These results areclose to those reported by others [6 7 17 35] which reportedthat udder infection rate was lower than that of doe In aprevious study [7] the left udder had a higher infection ratethan the right udder It has been suggested that this maybe due to the fact that the udder which is first milked ismore prone to infection than the one that is milked later[7] This occurs over a long time depending on right or lefthandedness As many people in the population are right-handed there tends to be more infection on the left udderas this is milked first

The most frequently isolated bacteria pathogen wascoagulase-negative Staphylococci (CNS) These results are inagreement with other studies [7 18 36ndash39] which concludedthat CNS is the causal agent of the majority of mastitis casesin dairy goats The members of the genus Staphylococci arethe most important mastitis-causing agents involved in allforms of mastitis even in other ruminants including goats[14] Staphylococci are known to cause all forms of mastitisranging from subclinical clinical and acute to gangrenous

mastitis [39] and are the major cause of culling in domesticruminants This is because Staphylococci are detectable onudder skin inside teat canal and in mammary glands andare transmitted through improper and unhygienic milkingprocedures [40]

In the current study a significant proportion of subclin-ical mastitis was due to S aureus Enterotoxin-secreting Saureus intramammary infections are associated with mastitisin dairy ruminants [8] Subclinical mastitis caused by thesebacteria apart from reducing milk yield can develop into theclinical form and is the mostly isolated pathogen in clinicalmastitis of small ruminants such as goats [13] The clinicalform of mastitis responds poorly to antibiotics because ofthe development of a tissue barrier that prevents penetrationof antibiotics to the site of infection and it is estimatedthat only 70 of these staphylococcal infections respond totherapy [25] Further S aureus secretes thermostable toxinswhich enhances the zoonotic role of these pathogens incausing foodborne diseases [38 40 41] Although heatingkills the bacteria the toxins remain in the food causing foodpoisoning

The other commonly isolated bacteria in this study werecoliforms which included Serratia Citrobacter KlebsiellaEnterobacter and E coli This is in agreement with otherstudies [14] which highlighted that coliforms bacteria are themain cause of environmental mastitis in domestic ruminantsPrevious studies have also reported that environmental mas-titis accounted for over 50 of bacteria isolated from milkof goats having mastitis [42] Coliforms thrive in unsanitaryhousing and living conditions of the dairy animals whichwere highly prevalent in the study area Some strains of E colisuch as the E coli 0157H7 cause bloody diarrhea in humanbeings [25]Citrobacter has also been shown to cause diarrheain human beings

In the present study the majority of CMT-positive milksamples yielded growth on bacterial culture High sensitivity(99) of CMT in diagnosis has been reported [18] A positivecorrelation between CMT and the presence of mastitispathogens in CMT-positive milk samples has also beenreported [21] This means that CMT is a reliable screeningtool in the detection of subclinical mastitis and can be usedto investigate subclinical mastitis in the dairy goat farms Thetest can be used by farmers to screen for subclinical mastitissince it is a simple field-based test which is less costly and iseasy to be carried out even by the farmers themselves

In this study there was significantly higher prevalence ofmastitis in does whose houses were cleaned every two weekscompared to those which were cleaned more frequentlyThese results are in agreement with those by others [7 13 1833 38 43] Environmental mastitis caused by organisms suchas coliforms tends to thrive in dirty environments and hencefrequent cleaning of goat houses is recommended

In the present study parity was found to be a riskfactor for subclinical mastitis This is in agreement withstudies undertaken by others [6 7 13 43 44] As CMTresults indicated that the prevalence of subclinical masti-tis increased with increasing parity it is recommended toincrease screening of does using CMT with increasing parityto curb the development of subclinical mastitis in a dairy

6 Journal of Veterinary Medicine

Table 4 Resistance pattern of bacteria isolated from milk of goats with subclinical mastitis to 6 antibiotics

Percentage () of resistanceBacteria Chloramphenicol Penicillin G Tetracycline Norfloxacin Streptomycin GentamycinS aureus (n=8) 0 100 25 25 0 0CNS (n=10) 0 100 20 0 10 0Serratia (n=9) 33 100 22 0 0 0Klebsiella (n=8) 25 100 37 0 0 25Citrobacter (n=7) 57 100 57 0 0 0Enterobacter (n=6) 0 100 17 0 0 0E coli (n=4) 50 100 0 0 0 0n = 52

herd Monitoring somatic cell counts on a regular basis andfollow-up investigations give an indication of the success ofgood animal husbandry and hygiene practices It thereforeforms an integral part ofmastitis control strategies and assistsin diagnosis and treatment [45]

All of the tested bacteria were resistant to Penicillin GSimilar resistance was reported in India [10] and in Brazil[46] In Pakistan [43] resistance of bacteria to Penicillin Gwas found to be 5769The current study shows an increasedresistance pattern of bacteria to Penicillin G and this isprobably due to the long time and extensive use of Penicillinin the treatment of mastitis [10]

Most bacteria in the current study were sensitive toStreptomycin Gentamycin and Norfloxacin A study inNigeria [47] reported a high resistance of bacterial isolatesto Streptomycin This could have been due to the overuseof the antibiotic in the treatment of goat diseases in thestudy area The sensitivity of bacterial isolates in this studyto Streptomycin may be because the antibiotic is rarely usedin mastitis treatment in the study area Studies in Bangladeshreported high resistance of S aureus to Streptomycin [48] Inanother study in Ethiopia [49] varying degrees of resistanceof bacteria to Chloramphenicol Gentamycin and Strep-tomycin were reported These studies show that there aredifferences in sensitivity to antibiotics based on the regionand the usage of a particular antibiotic

Multidrug resistance of bacteria to Tetracycline andChloramphenicol found in this work is comparable to those[7 29 35] which reportedmultidrug resistance of the bacteriaisolated from dairy goats to tetracyclines The resistanceto beta-lactams and tetracyclines is due to the fact thatthese antibiotics are commonly used in treatment of variousbacterial diseases in dairy animals [50] Results of the currentstudy also found that most bacteria are still susceptible toantibiotics as reported by others [7 29 35] hence they canstill be used in the treatment of subclinical mastitis

5 Conclusion

The current study shows that dairy goats in Thika EastSubcounty of Kenya had high prevalence of subclinicalmastitis Since farmers are not wary of the occurrence ofthe subclinical disease they could be having major economiclosses through reduction in milk yield Farmers in the study

area should be encouraged to use California Mastitis Test toscreen for subclinical mastitis as it is highly sensitive and isaffordable The genus Staphylococci was the main etiologicalagent of contagious subclinical mastitis The study showedthat hygiene plays a big role in the occurrence of subclinicalmastitis hence the farmers should ensure good sanitationand maintain strict cleaning schedules for goat houses toreduce the occurrence of subclinical mastitis Most broad-spectrum antibiotics are still effective in treating subclinicalmastitis However Penicillin G should not be used in thetreatment of subclinical mastitis The extension workers inthe area should train farmers on improved animal husbandrypractices such as good housing maintenance of regularcleaning schedule and proper milking procedures

Data Availability

The raw data on prevalence of subclinical mastitis riskfactors and antibiotic sensitivity used to support the findingsof this study are available from the corresponding authorupon request

Conflicts of Interest

The authors declare that they have no financial or personalrelationships that may have inappropriately influenced themin writing this article

Acknowledgments

The authors are grateful to Institute of Basic Sciences Tech-nology and Innovation Pan-African University (PAUSTI)and Jomo Kenyatta University of Agriculture and Technol-ogy (JKUAT) for financially sponsoring this research andacknowledge the technical assistance provided by JKUATstaff including Dr Lewis Macharia and Mr Muthanga

References

[1] A Merz R Stephan and S Johler ldquoStaphylococcus aureusisolates from goat and sheep milk seem to be closely relatedand differ from isolates detected from bovine milkrdquo Frontiersin Microbiology vol 7 pp 1ndash7 2016

Journal of Veterinary Medicine 7

[2] D P Kateete U Kabugo H Baluku et al ldquoPrevalence andantimicrobial susceptibility patterns of bacteria from milk-men and cows with clinical mastitis in and around KampalaUgandardquo PLoS ONE vol 8 no 5 2013

[3] S E Idriss V Tancin V Foltys K Kirchnerova DTancinova and M Vrskova ldquoRelationship between mastitiscausative pathogens and somatic cell counts in dairy cowsrdquoPotravinarstvo vol 7 no 1 pp 33ndash38 2013

[4] M E Haque ldquoRapid detection of subclinical mastitis in dairycowrdquo Journal of Fisheries amp Livestock Production vol 03 no 012014

[5] G F W Haenlein ldquoGoat milk in human nutritionrdquo SmallRuminant Research vol 51 no 2 pp 155ndash163 2004

[6] C Boscos A Stefanakis C Alexopoulos and F SamartzildquoPrevalence of subclinical mastitis and influence of breedparity stage of lactation andmammary bacteriological status onCoulter counter counts and California mastitis test in the milkof Saanen and autochthonous Greek goatsrdquo Small RuminantResearch vol 21 no 2 pp 139ndash147 1996

[7] C M Mbindyo to Characterise Dairy Goats Production inMount Kenya Region Determinition of Prevalence and RiskFactors of Subclinical Mastitis and Antibiotic Sensitivity of TheIsolates University of NairobiThesis 2014

[8] G A Contreras and J M Rodrıguez ldquoMastitis Comparativeetiology and epidemiologyrdquo Journal of Mammary Gland Biologyand Neoplasia vol 16 no 4 pp 339ndash356 2011

[9] M Amin M Samad and A A Rahman ldquoBacterial pathogensand risk factors associatedwithmastitis in black bengal goats inbangladeshrdquo Bangladesh Journal of Veterinary Medicine vol 9no 2 pp 155ndash159 2013

[10] S Priya and S Ayodha ldquoBacterial and antibiogram studiesof milk samples of clinical mastitis in goatsrdquo IOSR Journal ofAgriculture and Veterinary Science vol 9 no 6 pp 33ndash35 2016

[11] A Arguello ldquoTrends in goat research a reviewrdquo Journal ofApplied Animal Research vol 39 no 4 pp 429ndash434 2011

[12] J K Shearer and B B Harris ldquoMastitis in Dairy goatsrdquo Journalof Animal Science pp 1ndash7 2003

[13] D Bergonier R de Cremoux R Rupp G Lagriffoul andX Berthelot ldquoMastitis of dairy small ruminantsrdquo VeterinaryResearch vol 34 no 5 pp 689ndash716 2003

[14] O Radostits C C Gay D C Blood and W HinchcliffeeVeterinary Medicine Textbook of the Diseases of Cattle SheepGoats and Horses London UK 9th edition 2000

[15] httpwwwaceseduurban[16] A Raikwar and P C Shukla ldquoDiagnosis of mastitis in dairy

goatsrdquo International Journal of Agricultural Sciences and Veteri-nary Medicine vol 3 no 1 pp 58ndash61 2015

[17] A Contreras J C Corrales D Sierra and J Marco ldquoPreva-lence and aetiology of non-clinical intramammary infection inMurciano-Granadina goatsrdquo Small Ruminant Research vol 17no 1 pp 71ndash78 1995

[18] A Bourabah A Ayad L Boukraa S M Hammoudi and HBenbarek ldquoPrevalence and etiology of subclinical mastitis ingoats of the Tiaret Region Algeriardquo Global Veterinaria vol 11no 5 pp 604ndash608 2013

[19] P Maisi and I Riipinen ldquoUse of california mastitis test jv-acetyl-120573-glucosaminidase and antitrypsin to diagnose caprinesubclinicalmastitisrdquo Journal of Dairy Research vol 55 no 3 pp309ndash314 1988

[20] O W Schalm E J Carroll and N C Jain Bovine Mastitis Leaand Febiger Philadelphia PA USA 1971

[21] C M Mbindyo and L Bebora ldquoA cross-sectional study onthe prevalence of subclinical mastitis and antimicrobial sus-ceptibility patterns of the bacterial isolates in milk samples ofsmallholder dairy goats in KenyardquoAmerican Journal of ResearchCommunication vol 2 no 8 2014

[22] S P Oliver and S E Murinda ldquoAntimicrobial resistance ofmastitis pathogensrdquo Veterinary Clinics of North America - FoodAnimal Practice vol 28 no 2 pp 165ndash185 2012

[23] J Barlow ldquoMastitis therapy and antimicrobial susceptibilityA multispecies review with a focus on antibiotic treatment ofmastitis in dairy cattlerdquo Journal of Mammary Gland Biology andNeoplasia vol 16 no 4 pp 383ndash407 2011

[24] M Thrusfield Veterinary Epidemiology Blackwell PublishingCompany 2007

[25] P J Quinn M E Carter B Markey and G R CarterClinical Veterinary Microbiology Mosby Publishing Company1st edition 1994

[26] M CheesbroughDistrict Laboratory Practice in Tropical Coun-tries Cambridge University Press Cambridge UK 1st edition2006

[27] D H Bergey N R Krieg and J G Holt Bergeyrsquos Manualof Systematic Bacteriology Wilkins Baltimore MD USA 6thedition 1984

[28] CLSI Performance Standards for Antimicrobial SusceptibilityTesting Twenty Fifth Information Supplement Clinical andLaboratory Standards Institute Wayne PA USA 2015

[29] E N Ndegwa CMMulei and S JMMunyua ldquoPrevalence ofmicroorganisms associatedwith udder infections in dairy goatson small-scale farms in Kenyardquo Journal of the South AfricanVeterinary Association vol 72 no 2 pp 97-98 2001

[30] M Pirzada K K Marhi A A Kamboh et al ldquoPrevalence ofsubclinical mastitis in dairy goats caused by bacterial speciesrdquoJournal of Animal Health and Production 2016

[31] A K Mishra N Sharma D D Singh et al ldquoPrevalence andbacterial etiology of subclinical mastitis in goats reared inorganized farmsrdquo Veterinary World vol 11 no 1 pp 20ndash242018

[32] K Hristov B Kashamov R Pepovich and B Nikolov ldquoRiskfactors influencing the prevalence of subclinical mastitis ingoatsrdquo Scientific Works Series C Veterinary Medicine no 1 pp53ndash57 2016

[33] T J N K Mbilu ldquoStatus of mastitis in lactating goats at SokoineUniversity of agriculture and neighbouring smallholder farmsin Morogoro Municipality Tanzaniardquo Livestock Research forRural Development vol 19 no 3 pp 54ndash60 2007

[34] L Makau Prevalence of mastitis and associated risk risk factorsin dairy goats in Machokos County Kenya University of NairobiThesis 2017

[35] E N Ndegwa C M Mulei and S J M Munyua ldquoTheprevalence of subclinical mastitis in dairy goats in KenyardquoJournal of the South African Veterinary Association vol 71 no1 pp 25ndash27 2000

[36] A Sanchez A Contreras and J Corrales ldquoParity as a riskfactor for caprine subclinical intramammary infectionrdquo SmallRuminant Research vol 31 no 3 pp 197ndash201 1999

[37] S R Salaberry A B Saidenberg E Zuniga et al ldquoVirulencefactors genes of Staphylococcus spp isolated from caprinesubclinical mastitisrdquo Microbial Pathogenesis vol 85 pp 35ndash392015

[38] S Dore M Liciardi S Amatiste et al ldquoSurvey on smallruminant bacterial mastitis in Italy 2013-2014rdquo Small RuminantResearch vol 141 pp 91ndash93 2016

Journal of Veterinary Medicine 3

allowed to dry and streaking was done using a sterile loopThe plates were incubated at 37∘C for 24-48 hours

The morphology of the bacterial colonies obtained waschecked for the colony size shape texture and colourHaemolysis of the red blood cells in the sheep blood agar wasalso checked for by identification of the changes in the mediaaround and under the colonies After 48 hours plates with nogrowthwere recorded as no growth Plateswithmixed growthwere subcultured to obtain pure colonies

The gram-staining technique was used to differentiatebetween Gram-positive and Gram-negative bacteria [26] andalso to note the microscopic shape of the bacteria Biochemi-cal tests were used to further identify bacteria according tostandard methods [25] Identification of bacteria was pri-marily made on the basis of colony morphology haemolyticcharacteristics and gram-stain reaction and catalase testThe gram stain was used to differentiate between Gram-positive and Gram-negative isolates For the Gram-positiverods the catalase and mannitol test were further used foridentification of Corynebacterium The catalase tests using3 hydrogen peroxide were done to differentiate Streptococ-cus from Staphylococcus andMicrococcus Staphylococcus andMicrococcus species were identified based on their growthcharacteristics on Mannitol Salt Agar (Himedia India) slidecoagulase test using rabbit plasma catalase and oxidasetests (Himedia oxidase disks) Staphylococcus aureus was dif-ferentiated from coagulase-negative Staphylococci using theslide coagulase test S aureus isolates were further identifiedusing Polymerase Chain Reaction using S aureus-specific16S rRNA primers

The oxidase test was carried out on all Gram-negativeisolates to identify the family Enterobacteriaceae Oxidase-negative isolates were subcultured on MacConkey agar(Oxoid UK) to determine lactose fermentation Thereafterthe Triple Sugar Iron (Oxoid UK) (TSI) test citrate (SimmonCitrate Agar Himedia India) motility (Simmedia-HimediaIndia) indole (Tryptone broth Himedia India) Methyl RedVoges-Proskauer (Himedia India) urease (Urea broth baseHimedia India) mannitol and catalase tests were used foridentification of Gram-negative bacteria Dichotomous keys[25 27] were used for identification using results of haemoly-sis colonymorphology gram staining and biochemical tests

25 Antibiotic Susceptibility Testing Antibiotic susceptibilitytest was performed using the disc diffusion method [28]Pure cultures of isolates from the seven major isolatedbacteria were randomly selected (n=52) and standardized to05 McFarlandrsquos standard Mueller Hinton Agar (Himedia)plates were inoculated with standardized inoculums of thetest organism Six locally available and commonly usedantibiotics for treatment of mastitis in Kenya were selectedfor antibiotic susceptibility testing in the studyThe antibioticdiscs used were Penicillin G (10 IU) Gentamycin (10120583g)Streptomycin (10 120583g) Tetracycline (30 120583g) Chloramphenicol(30120583g) andNorfloxacin (10 120583g)The discs were placed on theagar surface The plates were incubated at 35∘C for 18 hoursThemeasurement of the inhibition zone was done and resultswere compared [28] Results were recorded as resistant orsusceptible to specific antibiotics

26 Statistical Analysis The coded data was entered intoMS Excel (Microsoft USA) spreadsheet and exported toSPSS (Microsoft USA) and R for data analysis Descriptivestatistics were presented as tables A chi square test was usedto evaluate associations between risk factors and mastitisinfection (plt005) Logistic regression was used to testindividual risk factors and their strength of association inmastitis infection The odds ratio was used to determine thestrength of associations identified in the logistic regressionprocedure

3 Results

31 Characteristics of Farms and Sampled Goats A total of41 farms were sampled from the study area Most of thefarms were a quarter acre (805) and the largest acreage wasone and a half acres The majority of goat houses (756)were raised timbers while others were earthen Zero grazing(854)was mostly practiced though some farmers practicedopen grazing and tethering Almost all the farmers (976)kept poultry Most of the farmers (634) were not awareof occurrence of mastitis in their flocks The frequency ofmilking the does ranged from once (805) to twice (195)a day All the farmers indicated that they did pre- andpostmilking teat cleaning procedures In most of the farms(951) the milk was consumed at home

32 Prevalence of Subclinical Mastitis and Identification ofthe Bacteria Using the California Mastitis Test (CMT) theprevalence of subclinical mastitis at doe and udder level wasfound to be 509 (56110) and 405 (89220) respectivelyOut of the samples which were positive by CMT 865(7789) gave a positive bacterial culture and 169 isolates ofbacteria were obtained from the cultures

The results of the bacteria isolated and their frequencyare given in Table 1 In descending order the isolatedbacteria were coagulase-negative Staphylococci Serratia sppCitrobacter sppKlebsiella spp Staphylococcus aureus Enter-obacter spp E coli Proteus sppCorynebacterium spp Mor-ganella spp Streptococcus spp Providencia sppMicrococcusspp and Staphylococcus intermedius

33 Relationship between Prevalence and Risk Factors Theresults of theCMTwere used to evaluate relationship betweenprevalence and risk factors In terms of doe breeds thehighest prevalence of subclinical mastitis was found inGerman alpine (667) followed by crosses and the leastaffected breed was the Kenyan alpine However there wasno significant (p=03934 OD=1059) difference between thebreeds and the prevalence of subclinical mastitis [Table 2]The highest percentage of goats with subclinical mastitis wasfound in goats aged 4 years and above (57) However therewas no significant [p=02347 OD=179] difference betweenthe prevalence of subclinical mastitis and the age of the doe[Table 2]

The highest prevalence (78) of subclinical mastitis wasfound in the does in the early lactation stage However therewas no significant difference (p=04251 OD=0803) between

4 Journal of Veterinary Medicine

Table 1 Bacteria isolated from dairy goats in Thika East Subcounty Kenya

Bacterial species Number of isolates Percentage ()Coagulase-negative Staphylococci 35 2070Serratia spp 33 1953Citrobacter spp 27 1598Klebsiella spp 19 1124Staphylococcus aureus 18 1065Enterobacter spp 11 651E coli 10 592Proteus spp 5 296Corynebacterium spp 3 178Morganella spp 3 178Streptococcus spp 2 118Providencia spp 1 059Micrococcus spp 1 059Staphylococcus intermedius 1 059Total 169 100

Table 2 Effect of breed age and lactation stage on prevalence of subclinical mastitis in dairy goats inThika East Subcounty as identified byCMT

Risk factor Proportion positive Prevalence of mastitis ()BreedGerman alpine 69 667Crosses 2646 565Toggenburg 1020 50Others 510 50Kenyan alpine 925 36Age (yrs)1 23 672 1839 463 1938 504 and above 1730 57Lactation stageEarly 1418 78Mid 1639 41Late 2653 49Early 1 day-3 months mid 3-6 months and late gt6 months

the occurrence of mastitis and the different lactation stages[Table 2]

The lowest prevalence of subclinical mastitis was found ingoats in the first parity [Table 3] and a significant (p=00477OD=1370) increase of prevalence was noted as the parityincreased

The highest prevalence of subclinical mastitis was foundin lactating does whose houses were cleaned fortnightly and asignificant [p=0022 OD=1047] increase was noted with lesscleaning [Table 3]

34 Antibiotic Susceptibility Testing Results S aureus wasmost sensitive to Gentamycin (100) Chloramphenicol(100) and Streptomycin (100) followed by Tetracycline(75) and Norfloxacin (75) All (100) coagulase-negative

Staphylococci (CNS) were sensitive to Gentamycin Chloram-phenicol and Norfloxacin Of the CNS isolates 90 weresensitive to Streptomycin and 80 toTetracycline All (100)the isolates tested were resistant to Penicillin G [Table 4]

Overall the isolates tested were most sensitive to Strep-tomycin (98) and least sensitive to Tetracycline (63)Of the tested isolates 31 of the isolates were resistant toTetracycline and 21 to Chloramphenicol

Multidrug resistance was found in 2 S aureus isolates(resistant to Penicillin G Tetracycline and Norfloxacin)3 Citrobacter isolates (resistant to Penicillin G Chloram-phenicol and Tetracycline) 1 Serratia isolate (resistant toPenicillin G Chloramphenicol and Tetracycline) and 2Ecoli isolates (resistant to Penicillin G Tetracycline andChloramphenicol)

Journal of Veterinary Medicine 5

Table 3 Effect of parity and cleaning schedule on prevalenceof subclinical mastitis in dairy goats in Thika East Subcounty asidentified by CMT

Risk factor Number of positive does Proportion ()Parity1 15 432 22 483 7 584 and above 12 71Cleaning scheduleWeekly 30 46Fortnightly 19 73Daily 4 33Irregular 3 42

4 Discussion

The findings of this work on the prevalence of subclinicalmastitis were higher than those reported in Kenya [29]Greece [6] Spain [17] Pakistan [30] and India [31] Theresults were comparable to the study in Bulgaria [32] whichfound prevalence of 442 The results were lower thanthose reported elsewhere in Kenya and Tanzania [7 33]which found prevalence of 57 and 77 respectively Thedifferences in prevalence of mastitis in various studies havebeen attributed to the differences in host and managementfactors which influence intramammary infection of goats [9]

Mastitis has a multifactorial nature with a clear inter-action between host agent and environment [24] Thedifferences in prevalence of studies undertaken in Kenya[7 34] could be due to differences in farm management andclimate of the various regions Further the high incidenceof subclinical mastitis may be attributed to poor hygienelack of standard milking procedures lack of proper pre- andpostudder washing and nonusage of teat dips [7]

The overall prevalence of subclinical mastitis at udderlevel was lower than that at the doe level These results areclose to those reported by others [6 7 17 35] which reportedthat udder infection rate was lower than that of doe In aprevious study [7] the left udder had a higher infection ratethan the right udder It has been suggested that this maybe due to the fact that the udder which is first milked ismore prone to infection than the one that is milked later[7] This occurs over a long time depending on right or lefthandedness As many people in the population are right-handed there tends to be more infection on the left udderas this is milked first

The most frequently isolated bacteria pathogen wascoagulase-negative Staphylococci (CNS) These results are inagreement with other studies [7 18 36ndash39] which concludedthat CNS is the causal agent of the majority of mastitis casesin dairy goats The members of the genus Staphylococci arethe most important mastitis-causing agents involved in allforms of mastitis even in other ruminants including goats[14] Staphylococci are known to cause all forms of mastitisranging from subclinical clinical and acute to gangrenous

mastitis [39] and are the major cause of culling in domesticruminants This is because Staphylococci are detectable onudder skin inside teat canal and in mammary glands andare transmitted through improper and unhygienic milkingprocedures [40]

In the current study a significant proportion of subclin-ical mastitis was due to S aureus Enterotoxin-secreting Saureus intramammary infections are associated with mastitisin dairy ruminants [8] Subclinical mastitis caused by thesebacteria apart from reducing milk yield can develop into theclinical form and is the mostly isolated pathogen in clinicalmastitis of small ruminants such as goats [13] The clinicalform of mastitis responds poorly to antibiotics because ofthe development of a tissue barrier that prevents penetrationof antibiotics to the site of infection and it is estimatedthat only 70 of these staphylococcal infections respond totherapy [25] Further S aureus secretes thermostable toxinswhich enhances the zoonotic role of these pathogens incausing foodborne diseases [38 40 41] Although heatingkills the bacteria the toxins remain in the food causing foodpoisoning

The other commonly isolated bacteria in this study werecoliforms which included Serratia Citrobacter KlebsiellaEnterobacter and E coli This is in agreement with otherstudies [14] which highlighted that coliforms bacteria are themain cause of environmental mastitis in domestic ruminantsPrevious studies have also reported that environmental mas-titis accounted for over 50 of bacteria isolated from milkof goats having mastitis [42] Coliforms thrive in unsanitaryhousing and living conditions of the dairy animals whichwere highly prevalent in the study area Some strains of E colisuch as the E coli 0157H7 cause bloody diarrhea in humanbeings [25]Citrobacter has also been shown to cause diarrheain human beings

In the present study the majority of CMT-positive milksamples yielded growth on bacterial culture High sensitivity(99) of CMT in diagnosis has been reported [18] A positivecorrelation between CMT and the presence of mastitispathogens in CMT-positive milk samples has also beenreported [21] This means that CMT is a reliable screeningtool in the detection of subclinical mastitis and can be usedto investigate subclinical mastitis in the dairy goat farms Thetest can be used by farmers to screen for subclinical mastitissince it is a simple field-based test which is less costly and iseasy to be carried out even by the farmers themselves

In this study there was significantly higher prevalence ofmastitis in does whose houses were cleaned every two weekscompared to those which were cleaned more frequentlyThese results are in agreement with those by others [7 13 1833 38 43] Environmental mastitis caused by organisms suchas coliforms tends to thrive in dirty environments and hencefrequent cleaning of goat houses is recommended

In the present study parity was found to be a riskfactor for subclinical mastitis This is in agreement withstudies undertaken by others [6 7 13 43 44] As CMTresults indicated that the prevalence of subclinical masti-tis increased with increasing parity it is recommended toincrease screening of does using CMT with increasing parityto curb the development of subclinical mastitis in a dairy

6 Journal of Veterinary Medicine

Table 4 Resistance pattern of bacteria isolated from milk of goats with subclinical mastitis to 6 antibiotics

Percentage () of resistanceBacteria Chloramphenicol Penicillin G Tetracycline Norfloxacin Streptomycin GentamycinS aureus (n=8) 0 100 25 25 0 0CNS (n=10) 0 100 20 0 10 0Serratia (n=9) 33 100 22 0 0 0Klebsiella (n=8) 25 100 37 0 0 25Citrobacter (n=7) 57 100 57 0 0 0Enterobacter (n=6) 0 100 17 0 0 0E coli (n=4) 50 100 0 0 0 0n = 52

herd Monitoring somatic cell counts on a regular basis andfollow-up investigations give an indication of the success ofgood animal husbandry and hygiene practices It thereforeforms an integral part ofmastitis control strategies and assistsin diagnosis and treatment [45]

All of the tested bacteria were resistant to Penicillin GSimilar resistance was reported in India [10] and in Brazil[46] In Pakistan [43] resistance of bacteria to Penicillin Gwas found to be 5769The current study shows an increasedresistance pattern of bacteria to Penicillin G and this isprobably due to the long time and extensive use of Penicillinin the treatment of mastitis [10]

Most bacteria in the current study were sensitive toStreptomycin Gentamycin and Norfloxacin A study inNigeria [47] reported a high resistance of bacterial isolatesto Streptomycin This could have been due to the overuseof the antibiotic in the treatment of goat diseases in thestudy area The sensitivity of bacterial isolates in this studyto Streptomycin may be because the antibiotic is rarely usedin mastitis treatment in the study area Studies in Bangladeshreported high resistance of S aureus to Streptomycin [48] Inanother study in Ethiopia [49] varying degrees of resistanceof bacteria to Chloramphenicol Gentamycin and Strep-tomycin were reported These studies show that there aredifferences in sensitivity to antibiotics based on the regionand the usage of a particular antibiotic

Multidrug resistance of bacteria to Tetracycline andChloramphenicol found in this work is comparable to those[7 29 35] which reportedmultidrug resistance of the bacteriaisolated from dairy goats to tetracyclines The resistanceto beta-lactams and tetracyclines is due to the fact thatthese antibiotics are commonly used in treatment of variousbacterial diseases in dairy animals [50] Results of the currentstudy also found that most bacteria are still susceptible toantibiotics as reported by others [7 29 35] hence they canstill be used in the treatment of subclinical mastitis

5 Conclusion

The current study shows that dairy goats in Thika EastSubcounty of Kenya had high prevalence of subclinicalmastitis Since farmers are not wary of the occurrence ofthe subclinical disease they could be having major economiclosses through reduction in milk yield Farmers in the study

area should be encouraged to use California Mastitis Test toscreen for subclinical mastitis as it is highly sensitive and isaffordable The genus Staphylococci was the main etiologicalagent of contagious subclinical mastitis The study showedthat hygiene plays a big role in the occurrence of subclinicalmastitis hence the farmers should ensure good sanitationand maintain strict cleaning schedules for goat houses toreduce the occurrence of subclinical mastitis Most broad-spectrum antibiotics are still effective in treating subclinicalmastitis However Penicillin G should not be used in thetreatment of subclinical mastitis The extension workers inthe area should train farmers on improved animal husbandrypractices such as good housing maintenance of regularcleaning schedule and proper milking procedures

Data Availability

The raw data on prevalence of subclinical mastitis riskfactors and antibiotic sensitivity used to support the findingsof this study are available from the corresponding authorupon request

Conflicts of Interest

The authors declare that they have no financial or personalrelationships that may have inappropriately influenced themin writing this article

Acknowledgments

The authors are grateful to Institute of Basic Sciences Tech-nology and Innovation Pan-African University (PAUSTI)and Jomo Kenyatta University of Agriculture and Technol-ogy (JKUAT) for financially sponsoring this research andacknowledge the technical assistance provided by JKUATstaff including Dr Lewis Macharia and Mr Muthanga

References

[1] A Merz R Stephan and S Johler ldquoStaphylococcus aureusisolates from goat and sheep milk seem to be closely relatedand differ from isolates detected from bovine milkrdquo Frontiersin Microbiology vol 7 pp 1ndash7 2016

Journal of Veterinary Medicine 7

[2] D P Kateete U Kabugo H Baluku et al ldquoPrevalence andantimicrobial susceptibility patterns of bacteria from milk-men and cows with clinical mastitis in and around KampalaUgandardquo PLoS ONE vol 8 no 5 2013

[3] S E Idriss V Tancin V Foltys K Kirchnerova DTancinova and M Vrskova ldquoRelationship between mastitiscausative pathogens and somatic cell counts in dairy cowsrdquoPotravinarstvo vol 7 no 1 pp 33ndash38 2013

[4] M E Haque ldquoRapid detection of subclinical mastitis in dairycowrdquo Journal of Fisheries amp Livestock Production vol 03 no 012014

[5] G F W Haenlein ldquoGoat milk in human nutritionrdquo SmallRuminant Research vol 51 no 2 pp 155ndash163 2004

[6] C Boscos A Stefanakis C Alexopoulos and F SamartzildquoPrevalence of subclinical mastitis and influence of breedparity stage of lactation andmammary bacteriological status onCoulter counter counts and California mastitis test in the milkof Saanen and autochthonous Greek goatsrdquo Small RuminantResearch vol 21 no 2 pp 139ndash147 1996

[7] C M Mbindyo to Characterise Dairy Goats Production inMount Kenya Region Determinition of Prevalence and RiskFactors of Subclinical Mastitis and Antibiotic Sensitivity of TheIsolates University of NairobiThesis 2014

[8] G A Contreras and J M Rodrıguez ldquoMastitis Comparativeetiology and epidemiologyrdquo Journal of Mammary Gland Biologyand Neoplasia vol 16 no 4 pp 339ndash356 2011

[9] M Amin M Samad and A A Rahman ldquoBacterial pathogensand risk factors associatedwithmastitis in black bengal goats inbangladeshrdquo Bangladesh Journal of Veterinary Medicine vol 9no 2 pp 155ndash159 2013

[10] S Priya and S Ayodha ldquoBacterial and antibiogram studiesof milk samples of clinical mastitis in goatsrdquo IOSR Journal ofAgriculture and Veterinary Science vol 9 no 6 pp 33ndash35 2016

[11] A Arguello ldquoTrends in goat research a reviewrdquo Journal ofApplied Animal Research vol 39 no 4 pp 429ndash434 2011

[12] J K Shearer and B B Harris ldquoMastitis in Dairy goatsrdquo Journalof Animal Science pp 1ndash7 2003

[13] D Bergonier R de Cremoux R Rupp G Lagriffoul andX Berthelot ldquoMastitis of dairy small ruminantsrdquo VeterinaryResearch vol 34 no 5 pp 689ndash716 2003

[14] O Radostits C C Gay D C Blood and W HinchcliffeeVeterinary Medicine Textbook of the Diseases of Cattle SheepGoats and Horses London UK 9th edition 2000

[15] httpwwwaceseduurban[16] A Raikwar and P C Shukla ldquoDiagnosis of mastitis in dairy

goatsrdquo International Journal of Agricultural Sciences and Veteri-nary Medicine vol 3 no 1 pp 58ndash61 2015

[17] A Contreras J C Corrales D Sierra and J Marco ldquoPreva-lence and aetiology of non-clinical intramammary infection inMurciano-Granadina goatsrdquo Small Ruminant Research vol 17no 1 pp 71ndash78 1995

[18] A Bourabah A Ayad L Boukraa S M Hammoudi and HBenbarek ldquoPrevalence and etiology of subclinical mastitis ingoats of the Tiaret Region Algeriardquo Global Veterinaria vol 11no 5 pp 604ndash608 2013

[19] P Maisi and I Riipinen ldquoUse of california mastitis test jv-acetyl-120573-glucosaminidase and antitrypsin to diagnose caprinesubclinicalmastitisrdquo Journal of Dairy Research vol 55 no 3 pp309ndash314 1988

[20] O W Schalm E J Carroll and N C Jain Bovine Mastitis Leaand Febiger Philadelphia PA USA 1971

[21] C M Mbindyo and L Bebora ldquoA cross-sectional study onthe prevalence of subclinical mastitis and antimicrobial sus-ceptibility patterns of the bacterial isolates in milk samples ofsmallholder dairy goats in KenyardquoAmerican Journal of ResearchCommunication vol 2 no 8 2014

[22] S P Oliver and S E Murinda ldquoAntimicrobial resistance ofmastitis pathogensrdquo Veterinary Clinics of North America - FoodAnimal Practice vol 28 no 2 pp 165ndash185 2012

[23] J Barlow ldquoMastitis therapy and antimicrobial susceptibilityA multispecies review with a focus on antibiotic treatment ofmastitis in dairy cattlerdquo Journal of Mammary Gland Biology andNeoplasia vol 16 no 4 pp 383ndash407 2011

[24] M Thrusfield Veterinary Epidemiology Blackwell PublishingCompany 2007

[25] P J Quinn M E Carter B Markey and G R CarterClinical Veterinary Microbiology Mosby Publishing Company1st edition 1994

[26] M CheesbroughDistrict Laboratory Practice in Tropical Coun-tries Cambridge University Press Cambridge UK 1st edition2006

[27] D H Bergey N R Krieg and J G Holt Bergeyrsquos Manualof Systematic Bacteriology Wilkins Baltimore MD USA 6thedition 1984

[28] CLSI Performance Standards for Antimicrobial SusceptibilityTesting Twenty Fifth Information Supplement Clinical andLaboratory Standards Institute Wayne PA USA 2015

[29] E N Ndegwa CMMulei and S JMMunyua ldquoPrevalence ofmicroorganisms associatedwith udder infections in dairy goatson small-scale farms in Kenyardquo Journal of the South AfricanVeterinary Association vol 72 no 2 pp 97-98 2001

[30] M Pirzada K K Marhi A A Kamboh et al ldquoPrevalence ofsubclinical mastitis in dairy goats caused by bacterial speciesrdquoJournal of Animal Health and Production 2016

[31] A K Mishra N Sharma D D Singh et al ldquoPrevalence andbacterial etiology of subclinical mastitis in goats reared inorganized farmsrdquo Veterinary World vol 11 no 1 pp 20ndash242018

[32] K Hristov B Kashamov R Pepovich and B Nikolov ldquoRiskfactors influencing the prevalence of subclinical mastitis ingoatsrdquo Scientific Works Series C Veterinary Medicine no 1 pp53ndash57 2016

[33] T J N K Mbilu ldquoStatus of mastitis in lactating goats at SokoineUniversity of agriculture and neighbouring smallholder farmsin Morogoro Municipality Tanzaniardquo Livestock Research forRural Development vol 19 no 3 pp 54ndash60 2007

[34] L Makau Prevalence of mastitis and associated risk risk factorsin dairy goats in Machokos County Kenya University of NairobiThesis 2017

[35] E N Ndegwa C M Mulei and S J M Munyua ldquoTheprevalence of subclinical mastitis in dairy goats in KenyardquoJournal of the South African Veterinary Association vol 71 no1 pp 25ndash27 2000

[36] A Sanchez A Contreras and J Corrales ldquoParity as a riskfactor for caprine subclinical intramammary infectionrdquo SmallRuminant Research vol 31 no 3 pp 197ndash201 1999

[37] S R Salaberry A B Saidenberg E Zuniga et al ldquoVirulencefactors genes of Staphylococcus spp isolated from caprinesubclinical mastitisrdquo Microbial Pathogenesis vol 85 pp 35ndash392015

[38] S Dore M Liciardi S Amatiste et al ldquoSurvey on smallruminant bacterial mastitis in Italy 2013-2014rdquo Small RuminantResearch vol 141 pp 91ndash93 2016

4 Journal of Veterinary Medicine

Table 1 Bacteria isolated from dairy goats in Thika East Subcounty Kenya

Bacterial species Number of isolates Percentage ()Coagulase-negative Staphylococci 35 2070Serratia spp 33 1953Citrobacter spp 27 1598Klebsiella spp 19 1124Staphylococcus aureus 18 1065Enterobacter spp 11 651E coli 10 592Proteus spp 5 296Corynebacterium spp 3 178Morganella spp 3 178Streptococcus spp 2 118Providencia spp 1 059Micrococcus spp 1 059Staphylococcus intermedius 1 059Total 169 100

Table 2 Effect of breed age and lactation stage on prevalence of subclinical mastitis in dairy goats inThika East Subcounty as identified byCMT

Risk factor Proportion positive Prevalence of mastitis ()BreedGerman alpine 69 667Crosses 2646 565Toggenburg 1020 50Others 510 50Kenyan alpine 925 36Age (yrs)1 23 672 1839 463 1938 504 and above 1730 57Lactation stageEarly 1418 78Mid 1639 41Late 2653 49Early 1 day-3 months mid 3-6 months and late gt6 months

the occurrence of mastitis and the different lactation stages[Table 2]

The lowest prevalence of subclinical mastitis was found ingoats in the first parity [Table 3] and a significant (p=00477OD=1370) increase of prevalence was noted as the parityincreased

The highest prevalence of subclinical mastitis was foundin lactating does whose houses were cleaned fortnightly and asignificant [p=0022 OD=1047] increase was noted with lesscleaning [Table 3]

34 Antibiotic Susceptibility Testing Results S aureus wasmost sensitive to Gentamycin (100) Chloramphenicol(100) and Streptomycin (100) followed by Tetracycline(75) and Norfloxacin (75) All (100) coagulase-negative

Staphylococci (CNS) were sensitive to Gentamycin Chloram-phenicol and Norfloxacin Of the CNS isolates 90 weresensitive to Streptomycin and 80 toTetracycline All (100)the isolates tested were resistant to Penicillin G [Table 4]

Overall the isolates tested were most sensitive to Strep-tomycin (98) and least sensitive to Tetracycline (63)Of the tested isolates 31 of the isolates were resistant toTetracycline and 21 to Chloramphenicol

Multidrug resistance was found in 2 S aureus isolates(resistant to Penicillin G Tetracycline and Norfloxacin)3 Citrobacter isolates (resistant to Penicillin G Chloram-phenicol and Tetracycline) 1 Serratia isolate (resistant toPenicillin G Chloramphenicol and Tetracycline) and 2Ecoli isolates (resistant to Penicillin G Tetracycline andChloramphenicol)

Journal of Veterinary Medicine 5

Table 3 Effect of parity and cleaning schedule on prevalenceof subclinical mastitis in dairy goats in Thika East Subcounty asidentified by CMT

Risk factor Number of positive does Proportion ()Parity1 15 432 22 483 7 584 and above 12 71Cleaning scheduleWeekly 30 46Fortnightly 19 73Daily 4 33Irregular 3 42

4 Discussion

The findings of this work on the prevalence of subclinicalmastitis were higher than those reported in Kenya [29]Greece [6] Spain [17] Pakistan [30] and India [31] Theresults were comparable to the study in Bulgaria [32] whichfound prevalence of 442 The results were lower thanthose reported elsewhere in Kenya and Tanzania [7 33]which found prevalence of 57 and 77 respectively Thedifferences in prevalence of mastitis in various studies havebeen attributed to the differences in host and managementfactors which influence intramammary infection of goats [9]

Mastitis has a multifactorial nature with a clear inter-action between host agent and environment [24] Thedifferences in prevalence of studies undertaken in Kenya[7 34] could be due to differences in farm management andclimate of the various regions Further the high incidenceof subclinical mastitis may be attributed to poor hygienelack of standard milking procedures lack of proper pre- andpostudder washing and nonusage of teat dips [7]

The overall prevalence of subclinical mastitis at udderlevel was lower than that at the doe level These results areclose to those reported by others [6 7 17 35] which reportedthat udder infection rate was lower than that of doe In aprevious study [7] the left udder had a higher infection ratethan the right udder It has been suggested that this maybe due to the fact that the udder which is first milked ismore prone to infection than the one that is milked later[7] This occurs over a long time depending on right or lefthandedness As many people in the population are right-handed there tends to be more infection on the left udderas this is milked first

The most frequently isolated bacteria pathogen wascoagulase-negative Staphylococci (CNS) These results are inagreement with other studies [7 18 36ndash39] which concludedthat CNS is the causal agent of the majority of mastitis casesin dairy goats The members of the genus Staphylococci arethe most important mastitis-causing agents involved in allforms of mastitis even in other ruminants including goats[14] Staphylococci are known to cause all forms of mastitisranging from subclinical clinical and acute to gangrenous

mastitis [39] and are the major cause of culling in domesticruminants This is because Staphylococci are detectable onudder skin inside teat canal and in mammary glands andare transmitted through improper and unhygienic milkingprocedures [40]

In the current study a significant proportion of subclin-ical mastitis was due to S aureus Enterotoxin-secreting Saureus intramammary infections are associated with mastitisin dairy ruminants [8] Subclinical mastitis caused by thesebacteria apart from reducing milk yield can develop into theclinical form and is the mostly isolated pathogen in clinicalmastitis of small ruminants such as goats [13] The clinicalform of mastitis responds poorly to antibiotics because ofthe development of a tissue barrier that prevents penetrationof antibiotics to the site of infection and it is estimatedthat only 70 of these staphylococcal infections respond totherapy [25] Further S aureus secretes thermostable toxinswhich enhances the zoonotic role of these pathogens incausing foodborne diseases [38 40 41] Although heatingkills the bacteria the toxins remain in the food causing foodpoisoning

The other commonly isolated bacteria in this study werecoliforms which included Serratia Citrobacter KlebsiellaEnterobacter and E coli This is in agreement with otherstudies [14] which highlighted that coliforms bacteria are themain cause of environmental mastitis in domestic ruminantsPrevious studies have also reported that environmental mas-titis accounted for over 50 of bacteria isolated from milkof goats having mastitis [42] Coliforms thrive in unsanitaryhousing and living conditions of the dairy animals whichwere highly prevalent in the study area Some strains of E colisuch as the E coli 0157H7 cause bloody diarrhea in humanbeings [25]Citrobacter has also been shown to cause diarrheain human beings

In the present study the majority of CMT-positive milksamples yielded growth on bacterial culture High sensitivity(99) of CMT in diagnosis has been reported [18] A positivecorrelation between CMT and the presence of mastitispathogens in CMT-positive milk samples has also beenreported [21] This means that CMT is a reliable screeningtool in the detection of subclinical mastitis and can be usedto investigate subclinical mastitis in the dairy goat farms Thetest can be used by farmers to screen for subclinical mastitissince it is a simple field-based test which is less costly and iseasy to be carried out even by the farmers themselves

In this study there was significantly higher prevalence ofmastitis in does whose houses were cleaned every two weekscompared to those which were cleaned more frequentlyThese results are in agreement with those by others [7 13 1833 38 43] Environmental mastitis caused by organisms suchas coliforms tends to thrive in dirty environments and hencefrequent cleaning of goat houses is recommended

In the present study parity was found to be a riskfactor for subclinical mastitis This is in agreement withstudies undertaken by others [6 7 13 43 44] As CMTresults indicated that the prevalence of subclinical masti-tis increased with increasing parity it is recommended toincrease screening of does using CMT with increasing parityto curb the development of subclinical mastitis in a dairy

6 Journal of Veterinary Medicine

Table 4 Resistance pattern of bacteria isolated from milk of goats with subclinical mastitis to 6 antibiotics

Percentage () of resistanceBacteria Chloramphenicol Penicillin G Tetracycline Norfloxacin Streptomycin GentamycinS aureus (n=8) 0 100 25 25 0 0CNS (n=10) 0 100 20 0 10 0Serratia (n=9) 33 100 22 0 0 0Klebsiella (n=8) 25 100 37 0 0 25Citrobacter (n=7) 57 100 57 0 0 0Enterobacter (n=6) 0 100 17 0 0 0E coli (n=4) 50 100 0 0 0 0n = 52

herd Monitoring somatic cell counts on a regular basis andfollow-up investigations give an indication of the success ofgood animal husbandry and hygiene practices It thereforeforms an integral part ofmastitis control strategies and assistsin diagnosis and treatment [45]

All of the tested bacteria were resistant to Penicillin GSimilar resistance was reported in India [10] and in Brazil[46] In Pakistan [43] resistance of bacteria to Penicillin Gwas found to be 5769The current study shows an increasedresistance pattern of bacteria to Penicillin G and this isprobably due to the long time and extensive use of Penicillinin the treatment of mastitis [10]

Most bacteria in the current study were sensitive toStreptomycin Gentamycin and Norfloxacin A study inNigeria [47] reported a high resistance of bacterial isolatesto Streptomycin This could have been due to the overuseof the antibiotic in the treatment of goat diseases in thestudy area The sensitivity of bacterial isolates in this studyto Streptomycin may be because the antibiotic is rarely usedin mastitis treatment in the study area Studies in Bangladeshreported high resistance of S aureus to Streptomycin [48] Inanother study in Ethiopia [49] varying degrees of resistanceof bacteria to Chloramphenicol Gentamycin and Strep-tomycin were reported These studies show that there aredifferences in sensitivity to antibiotics based on the regionand the usage of a particular antibiotic

Multidrug resistance of bacteria to Tetracycline andChloramphenicol found in this work is comparable to those[7 29 35] which reportedmultidrug resistance of the bacteriaisolated from dairy goats to tetracyclines The resistanceto beta-lactams and tetracyclines is due to the fact thatthese antibiotics are commonly used in treatment of variousbacterial diseases in dairy animals [50] Results of the currentstudy also found that most bacteria are still susceptible toantibiotics as reported by others [7 29 35] hence they canstill be used in the treatment of subclinical mastitis

5 Conclusion

The current study shows that dairy goats in Thika EastSubcounty of Kenya had high prevalence of subclinicalmastitis Since farmers are not wary of the occurrence ofthe subclinical disease they could be having major economiclosses through reduction in milk yield Farmers in the study

area should be encouraged to use California Mastitis Test toscreen for subclinical mastitis as it is highly sensitive and isaffordable The genus Staphylococci was the main etiologicalagent of contagious subclinical mastitis The study showedthat hygiene plays a big role in the occurrence of subclinicalmastitis hence the farmers should ensure good sanitationand maintain strict cleaning schedules for goat houses toreduce the occurrence of subclinical mastitis Most broad-spectrum antibiotics are still effective in treating subclinicalmastitis However Penicillin G should not be used in thetreatment of subclinical mastitis The extension workers inthe area should train farmers on improved animal husbandrypractices such as good housing maintenance of regularcleaning schedule and proper milking procedures

Data Availability

The raw data on prevalence of subclinical mastitis riskfactors and antibiotic sensitivity used to support the findingsof this study are available from the corresponding authorupon request

Conflicts of Interest

The authors declare that they have no financial or personalrelationships that may have inappropriately influenced themin writing this article

Acknowledgments

The authors are grateful to Institute of Basic Sciences Tech-nology and Innovation Pan-African University (PAUSTI)and Jomo Kenyatta University of Agriculture and Technol-ogy (JKUAT) for financially sponsoring this research andacknowledge the technical assistance provided by JKUATstaff including Dr Lewis Macharia and Mr Muthanga

References

[1] A Merz R Stephan and S Johler ldquoStaphylococcus aureusisolates from goat and sheep milk seem to be closely relatedand differ from isolates detected from bovine milkrdquo Frontiersin Microbiology vol 7 pp 1ndash7 2016

Journal of Veterinary Medicine 7

[2] D P Kateete U Kabugo H Baluku et al ldquoPrevalence andantimicrobial susceptibility patterns of bacteria from milk-men and cows with clinical mastitis in and around KampalaUgandardquo PLoS ONE vol 8 no 5 2013

[3] S E Idriss V Tancin V Foltys K Kirchnerova DTancinova and M Vrskova ldquoRelationship between mastitiscausative pathogens and somatic cell counts in dairy cowsrdquoPotravinarstvo vol 7 no 1 pp 33ndash38 2013

[4] M E Haque ldquoRapid detection of subclinical mastitis in dairycowrdquo Journal of Fisheries amp Livestock Production vol 03 no 012014

[5] G F W Haenlein ldquoGoat milk in human nutritionrdquo SmallRuminant Research vol 51 no 2 pp 155ndash163 2004

[6] C Boscos A Stefanakis C Alexopoulos and F SamartzildquoPrevalence of subclinical mastitis and influence of breedparity stage of lactation andmammary bacteriological status onCoulter counter counts and California mastitis test in the milkof Saanen and autochthonous Greek goatsrdquo Small RuminantResearch vol 21 no 2 pp 139ndash147 1996

[7] C M Mbindyo to Characterise Dairy Goats Production inMount Kenya Region Determinition of Prevalence and RiskFactors of Subclinical Mastitis and Antibiotic Sensitivity of TheIsolates University of NairobiThesis 2014

[8] G A Contreras and J M Rodrıguez ldquoMastitis Comparativeetiology and epidemiologyrdquo Journal of Mammary Gland Biologyand Neoplasia vol 16 no 4 pp 339ndash356 2011

[9] M Amin M Samad and A A Rahman ldquoBacterial pathogensand risk factors associatedwithmastitis in black bengal goats inbangladeshrdquo Bangladesh Journal of Veterinary Medicine vol 9no 2 pp 155ndash159 2013

[10] S Priya and S Ayodha ldquoBacterial and antibiogram studiesof milk samples of clinical mastitis in goatsrdquo IOSR Journal ofAgriculture and Veterinary Science vol 9 no 6 pp 33ndash35 2016

[11] A Arguello ldquoTrends in goat research a reviewrdquo Journal ofApplied Animal Research vol 39 no 4 pp 429ndash434 2011

[12] J K Shearer and B B Harris ldquoMastitis in Dairy goatsrdquo Journalof Animal Science pp 1ndash7 2003

[13] D Bergonier R de Cremoux R Rupp G Lagriffoul andX Berthelot ldquoMastitis of dairy small ruminantsrdquo VeterinaryResearch vol 34 no 5 pp 689ndash716 2003

[14] O Radostits C C Gay D C Blood and W HinchcliffeeVeterinary Medicine Textbook of the Diseases of Cattle SheepGoats and Horses London UK 9th edition 2000

[15] httpwwwaceseduurban[16] A Raikwar and P C Shukla ldquoDiagnosis of mastitis in dairy

goatsrdquo International Journal of Agricultural Sciences and Veteri-nary Medicine vol 3 no 1 pp 58ndash61 2015

[17] A Contreras J C Corrales D Sierra and J Marco ldquoPreva-lence and aetiology of non-clinical intramammary infection inMurciano-Granadina goatsrdquo Small Ruminant Research vol 17no 1 pp 71ndash78 1995

[18] A Bourabah A Ayad L Boukraa S M Hammoudi and HBenbarek ldquoPrevalence and etiology of subclinical mastitis ingoats of the Tiaret Region Algeriardquo Global Veterinaria vol 11no 5 pp 604ndash608 2013

[19] P Maisi and I Riipinen ldquoUse of california mastitis test jv-acetyl-120573-glucosaminidase and antitrypsin to diagnose caprinesubclinicalmastitisrdquo Journal of Dairy Research vol 55 no 3 pp309ndash314 1988

[20] O W Schalm E J Carroll and N C Jain Bovine Mastitis Leaand Febiger Philadelphia PA USA 1971

[21] C M Mbindyo and L Bebora ldquoA cross-sectional study onthe prevalence of subclinical mastitis and antimicrobial sus-ceptibility patterns of the bacterial isolates in milk samples ofsmallholder dairy goats in KenyardquoAmerican Journal of ResearchCommunication vol 2 no 8 2014

[22] S P Oliver and S E Murinda ldquoAntimicrobial resistance ofmastitis pathogensrdquo Veterinary Clinics of North America - FoodAnimal Practice vol 28 no 2 pp 165ndash185 2012

[23] J Barlow ldquoMastitis therapy and antimicrobial susceptibilityA multispecies review with a focus on antibiotic treatment ofmastitis in dairy cattlerdquo Journal of Mammary Gland Biology andNeoplasia vol 16 no 4 pp 383ndash407 2011

[24] M Thrusfield Veterinary Epidemiology Blackwell PublishingCompany 2007

[25] P J Quinn M E Carter B Markey and G R CarterClinical Veterinary Microbiology Mosby Publishing Company1st edition 1994

[26] M CheesbroughDistrict Laboratory Practice in Tropical Coun-tries Cambridge University Press Cambridge UK 1st edition2006

[27] D H Bergey N R Krieg and J G Holt Bergeyrsquos Manualof Systematic Bacteriology Wilkins Baltimore MD USA 6thedition 1984

[28] CLSI Performance Standards for Antimicrobial SusceptibilityTesting Twenty Fifth Information Supplement Clinical andLaboratory Standards Institute Wayne PA USA 2015

[29] E N Ndegwa CMMulei and S JMMunyua ldquoPrevalence ofmicroorganisms associatedwith udder infections in dairy goatson small-scale farms in Kenyardquo Journal of the South AfricanVeterinary Association vol 72 no 2 pp 97-98 2001

[30] M Pirzada K K Marhi A A Kamboh et al ldquoPrevalence ofsubclinical mastitis in dairy goats caused by bacterial speciesrdquoJournal of Animal Health and Production 2016

[31] A K Mishra N Sharma D D Singh et al ldquoPrevalence andbacterial etiology of subclinical mastitis in goats reared inorganized farmsrdquo Veterinary World vol 11 no 1 pp 20ndash242018

[32] K Hristov B Kashamov R Pepovich and B Nikolov ldquoRiskfactors influencing the prevalence of subclinical mastitis ingoatsrdquo Scientific Works Series C Veterinary Medicine no 1 pp53ndash57 2016

[33] T J N K Mbilu ldquoStatus of mastitis in lactating goats at SokoineUniversity of agriculture and neighbouring smallholder farmsin Morogoro Municipality Tanzaniardquo Livestock Research forRural Development vol 19 no 3 pp 54ndash60 2007

[34] L Makau Prevalence of mastitis and associated risk risk factorsin dairy goats in Machokos County Kenya University of NairobiThesis 2017

[35] E N Ndegwa C M Mulei and S J M Munyua ldquoTheprevalence of subclinical mastitis in dairy goats in KenyardquoJournal of the South African Veterinary Association vol 71 no1 pp 25ndash27 2000

[36] A Sanchez A Contreras and J Corrales ldquoParity as a riskfactor for caprine subclinical intramammary infectionrdquo SmallRuminant Research vol 31 no 3 pp 197ndash201 1999

[37] S R Salaberry A B Saidenberg E Zuniga et al ldquoVirulencefactors genes of Staphylococcus spp isolated from caprinesubclinical mastitisrdquo Microbial Pathogenesis vol 85 pp 35ndash392015

[38] S Dore M Liciardi S Amatiste et al ldquoSurvey on smallruminant bacterial mastitis in Italy 2013-2014rdquo Small RuminantResearch vol 141 pp 91ndash93 2016

Journal of Veterinary Medicine 5

Table 3 Effect of parity and cleaning schedule on prevalenceof subclinical mastitis in dairy goats in Thika East Subcounty asidentified by CMT

Risk factor Number of positive does Proportion ()Parity1 15 432 22 483 7 584 and above 12 71Cleaning scheduleWeekly 30 46Fortnightly 19 73Daily 4 33Irregular 3 42

4 Discussion

The findings of this work on the prevalence of subclinicalmastitis were higher than those reported in Kenya [29]Greece [6] Spain [17] Pakistan [30] and India [31] Theresults were comparable to the study in Bulgaria [32] whichfound prevalence of 442 The results were lower thanthose reported elsewhere in Kenya and Tanzania [7 33]which found prevalence of 57 and 77 respectively Thedifferences in prevalence of mastitis in various studies havebeen attributed to the differences in host and managementfactors which influence intramammary infection of goats [9]

Mastitis has a multifactorial nature with a clear inter-action between host agent and environment [24] Thedifferences in prevalence of studies undertaken in Kenya[7 34] could be due to differences in farm management andclimate of the various regions Further the high incidenceof subclinical mastitis may be attributed to poor hygienelack of standard milking procedures lack of proper pre- andpostudder washing and nonusage of teat dips [7]

The overall prevalence of subclinical mastitis at udderlevel was lower than that at the doe level These results areclose to those reported by others [6 7 17 35] which reportedthat udder infection rate was lower than that of doe In aprevious study [7] the left udder had a higher infection ratethan the right udder It has been suggested that this maybe due to the fact that the udder which is first milked ismore prone to infection than the one that is milked later[7] This occurs over a long time depending on right or lefthandedness As many people in the population are right-handed there tends to be more infection on the left udderas this is milked first

The most frequently isolated bacteria pathogen wascoagulase-negative Staphylococci (CNS) These results are inagreement with other studies [7 18 36ndash39] which concludedthat CNS is the causal agent of the majority of mastitis casesin dairy goats The members of the genus Staphylococci arethe most important mastitis-causing agents involved in allforms of mastitis even in other ruminants including goats[14] Staphylococci are known to cause all forms of mastitisranging from subclinical clinical and acute to gangrenous

mastitis [39] and are the major cause of culling in domesticruminants This is because Staphylococci are detectable onudder skin inside teat canal and in mammary glands andare transmitted through improper and unhygienic milkingprocedures [40]

In the current study a significant proportion of subclin-ical mastitis was due to S aureus Enterotoxin-secreting Saureus intramammary infections are associated with mastitisin dairy ruminants [8] Subclinical mastitis caused by thesebacteria apart from reducing milk yield can develop into theclinical form and is the mostly isolated pathogen in clinicalmastitis of small ruminants such as goats [13] The clinicalform of mastitis responds poorly to antibiotics because ofthe development of a tissue barrier that prevents penetrationof antibiotics to the site of infection and it is estimatedthat only 70 of these staphylococcal infections respond totherapy [25] Further S aureus secretes thermostable toxinswhich enhances the zoonotic role of these pathogens incausing foodborne diseases [38 40 41] Although heatingkills the bacteria the toxins remain in the food causing foodpoisoning

The other commonly isolated bacteria in this study werecoliforms which included Serratia Citrobacter KlebsiellaEnterobacter and E coli This is in agreement with otherstudies [14] which highlighted that coliforms bacteria are themain cause of environmental mastitis in domestic ruminantsPrevious studies have also reported that environmental mas-titis accounted for over 50 of bacteria isolated from milkof goats having mastitis [42] Coliforms thrive in unsanitaryhousing and living conditions of the dairy animals whichwere highly prevalent in the study area Some strains of E colisuch as the E coli 0157H7 cause bloody diarrhea in humanbeings [25]Citrobacter has also been shown to cause diarrheain human beings

In the present study the majority of CMT-positive milksamples yielded growth on bacterial culture High sensitivity(99) of CMT in diagnosis has been reported [18] A positivecorrelation between CMT and the presence of mastitispathogens in CMT-positive milk samples has also beenreported [21] This means that CMT is a reliable screeningtool in the detection of subclinical mastitis and can be usedto investigate subclinical mastitis in the dairy goat farms Thetest can be used by farmers to screen for subclinical mastitissince it is a simple field-based test which is less costly and iseasy to be carried out even by the farmers themselves

In this study there was significantly higher prevalence ofmastitis in does whose houses were cleaned every two weekscompared to those which were cleaned more frequentlyThese results are in agreement with those by others [7 13 1833 38 43] Environmental mastitis caused by organisms suchas coliforms tends to thrive in dirty environments and hencefrequent cleaning of goat houses is recommended

In the present study parity was found to be a riskfactor for subclinical mastitis This is in agreement withstudies undertaken by others [6 7 13 43 44] As CMTresults indicated that the prevalence of subclinical masti-tis increased with increasing parity it is recommended toincrease screening of does using CMT with increasing parityto curb the development of subclinical mastitis in a dairy

6 Journal of Veterinary Medicine

Table 4 Resistance pattern of bacteria isolated from milk of goats with subclinical mastitis to 6 antibiotics

Percentage () of resistanceBacteria Chloramphenicol Penicillin G Tetracycline Norfloxacin Streptomycin GentamycinS aureus (n=8) 0 100 25 25 0 0CNS (n=10) 0 100 20 0 10 0Serratia (n=9) 33 100 22 0 0 0Klebsiella (n=8) 25 100 37 0 0 25Citrobacter (n=7) 57 100 57 0 0 0Enterobacter (n=6) 0 100 17 0 0 0E coli (n=4) 50 100 0 0 0 0n = 52

herd Monitoring somatic cell counts on a regular basis andfollow-up investigations give an indication of the success ofgood animal husbandry and hygiene practices It thereforeforms an integral part ofmastitis control strategies and assistsin diagnosis and treatment [45]

All of the tested bacteria were resistant to Penicillin GSimilar resistance was reported in India [10] and in Brazil[46] In Pakistan [43] resistance of bacteria to Penicillin Gwas found to be 5769The current study shows an increasedresistance pattern of bacteria to Penicillin G and this isprobably due to the long time and extensive use of Penicillinin the treatment of mastitis [10]

Most bacteria in the current study were sensitive toStreptomycin Gentamycin and Norfloxacin A study inNigeria [47] reported a high resistance of bacterial isolatesto Streptomycin This could have been due to the overuseof the antibiotic in the treatment of goat diseases in thestudy area The sensitivity of bacterial isolates in this studyto Streptomycin may be because the antibiotic is rarely usedin mastitis treatment in the study area Studies in Bangladeshreported high resistance of S aureus to Streptomycin [48] Inanother study in Ethiopia [49] varying degrees of resistanceof bacteria to Chloramphenicol Gentamycin and Strep-tomycin were reported These studies show that there aredifferences in sensitivity to antibiotics based on the regionand the usage of a particular antibiotic

Multidrug resistance of bacteria to Tetracycline andChloramphenicol found in this work is comparable to those[7 29 35] which reportedmultidrug resistance of the bacteriaisolated from dairy goats to tetracyclines The resistanceto beta-lactams and tetracyclines is due to the fact thatthese antibiotics are commonly used in treatment of variousbacterial diseases in dairy animals [50] Results of the currentstudy also found that most bacteria are still susceptible toantibiotics as reported by others [7 29 35] hence they canstill be used in the treatment of subclinical mastitis

5 Conclusion

The current study shows that dairy goats in Thika EastSubcounty of Kenya had high prevalence of subclinicalmastitis Since farmers are not wary of the occurrence ofthe subclinical disease they could be having major economiclosses through reduction in milk yield Farmers in the study

area should be encouraged to use California Mastitis Test toscreen for subclinical mastitis as it is highly sensitive and isaffordable The genus Staphylococci was the main etiologicalagent of contagious subclinical mastitis The study showedthat hygiene plays a big role in the occurrence of subclinicalmastitis hence the farmers should ensure good sanitationand maintain strict cleaning schedules for goat houses toreduce the occurrence of subclinical mastitis Most broad-spectrum antibiotics are still effective in treating subclinicalmastitis However Penicillin G should not be used in thetreatment of subclinical mastitis The extension workers inthe area should train farmers on improved animal husbandrypractices such as good housing maintenance of regularcleaning schedule and proper milking procedures

Data Availability

The raw data on prevalence of subclinical mastitis riskfactors and antibiotic sensitivity used to support the findingsof this study are available from the corresponding authorupon request

Conflicts of Interest

The authors declare that they have no financial or personalrelationships that may have inappropriately influenced themin writing this article

Acknowledgments

The authors are grateful to Institute of Basic Sciences Tech-nology and Innovation Pan-African University (PAUSTI)and Jomo Kenyatta University of Agriculture and Technol-ogy (JKUAT) for financially sponsoring this research andacknowledge the technical assistance provided by JKUATstaff including Dr Lewis Macharia and Mr Muthanga

References

[1] A Merz R Stephan and S Johler ldquoStaphylococcus aureusisolates from goat and sheep milk seem to be closely relatedand differ from isolates detected from bovine milkrdquo Frontiersin Microbiology vol 7 pp 1ndash7 2016

Journal of Veterinary Medicine 7

[2] D P Kateete U Kabugo H Baluku et al ldquoPrevalence andantimicrobial susceptibility patterns of bacteria from milk-men and cows with clinical mastitis in and around KampalaUgandardquo PLoS ONE vol 8 no 5 2013

[3] S E Idriss V Tancin V Foltys K Kirchnerova DTancinova and M Vrskova ldquoRelationship between mastitiscausative pathogens and somatic cell counts in dairy cowsrdquoPotravinarstvo vol 7 no 1 pp 33ndash38 2013

[4] M E Haque ldquoRapid detection of subclinical mastitis in dairycowrdquo Journal of Fisheries amp Livestock Production vol 03 no 012014

[5] G F W Haenlein ldquoGoat milk in human nutritionrdquo SmallRuminant Research vol 51 no 2 pp 155ndash163 2004

[6] C Boscos A Stefanakis C Alexopoulos and F SamartzildquoPrevalence of subclinical mastitis and influence of breedparity stage of lactation andmammary bacteriological status onCoulter counter counts and California mastitis test in the milkof Saanen and autochthonous Greek goatsrdquo Small RuminantResearch vol 21 no 2 pp 139ndash147 1996

[7] C M Mbindyo to Characterise Dairy Goats Production inMount Kenya Region Determinition of Prevalence and RiskFactors of Subclinical Mastitis and Antibiotic Sensitivity of TheIsolates University of NairobiThesis 2014

[8] G A Contreras and J M Rodrıguez ldquoMastitis Comparativeetiology and epidemiologyrdquo Journal of Mammary Gland Biologyand Neoplasia vol 16 no 4 pp 339ndash356 2011

[9] M Amin M Samad and A A Rahman ldquoBacterial pathogensand risk factors associatedwithmastitis in black bengal goats inbangladeshrdquo Bangladesh Journal of Veterinary Medicine vol 9no 2 pp 155ndash159 2013

[10] S Priya and S Ayodha ldquoBacterial and antibiogram studiesof milk samples of clinical mastitis in goatsrdquo IOSR Journal ofAgriculture and Veterinary Science vol 9 no 6 pp 33ndash35 2016

[11] A Arguello ldquoTrends in goat research a reviewrdquo Journal ofApplied Animal Research vol 39 no 4 pp 429ndash434 2011

[12] J K Shearer and B B Harris ldquoMastitis in Dairy goatsrdquo Journalof Animal Science pp 1ndash7 2003

[13] D Bergonier R de Cremoux R Rupp G Lagriffoul andX Berthelot ldquoMastitis of dairy small ruminantsrdquo VeterinaryResearch vol 34 no 5 pp 689ndash716 2003

[14] O Radostits C C Gay D C Blood and W HinchcliffeeVeterinary Medicine Textbook of the Diseases of Cattle SheepGoats and Horses London UK 9th edition 2000

[15] httpwwwaceseduurban[16] A Raikwar and P C Shukla ldquoDiagnosis of mastitis in dairy

goatsrdquo International Journal of Agricultural Sciences and Veteri-nary Medicine vol 3 no 1 pp 58ndash61 2015

[17] A Contreras J C Corrales D Sierra and J Marco ldquoPreva-lence and aetiology of non-clinical intramammary infection inMurciano-Granadina goatsrdquo Small Ruminant Research vol 17no 1 pp 71ndash78 1995

[18] A Bourabah A Ayad L Boukraa S M Hammoudi and HBenbarek ldquoPrevalence and etiology of subclinical mastitis ingoats of the Tiaret Region Algeriardquo Global Veterinaria vol 11no 5 pp 604ndash608 2013

[19] P Maisi and I Riipinen ldquoUse of california mastitis test jv-acetyl-120573-glucosaminidase and antitrypsin to diagnose caprinesubclinicalmastitisrdquo Journal of Dairy Research vol 55 no 3 pp309ndash314 1988

[20] O W Schalm E J Carroll and N C Jain Bovine Mastitis Leaand Febiger Philadelphia PA USA 1971

[21] C M Mbindyo and L Bebora ldquoA cross-sectional study onthe prevalence of subclinical mastitis and antimicrobial sus-ceptibility patterns of the bacterial isolates in milk samples ofsmallholder dairy goats in KenyardquoAmerican Journal of ResearchCommunication vol 2 no 8 2014

[22] S P Oliver and S E Murinda ldquoAntimicrobial resistance ofmastitis pathogensrdquo Veterinary Clinics of North America - FoodAnimal Practice vol 28 no 2 pp 165ndash185 2012

[23] J Barlow ldquoMastitis therapy and antimicrobial susceptibilityA multispecies review with a focus on antibiotic treatment ofmastitis in dairy cattlerdquo Journal of Mammary Gland Biology andNeoplasia vol 16 no 4 pp 383ndash407 2011

[24] M Thrusfield Veterinary Epidemiology Blackwell PublishingCompany 2007

[25] P J Quinn M E Carter B Markey and G R CarterClinical Veterinary Microbiology Mosby Publishing Company1st edition 1994

[26] M CheesbroughDistrict Laboratory Practice in Tropical Coun-tries Cambridge University Press Cambridge UK 1st edition2006

[27] D H Bergey N R Krieg and J G Holt Bergeyrsquos Manualof Systematic Bacteriology Wilkins Baltimore MD USA 6thedition 1984

[28] CLSI Performance Standards for Antimicrobial SusceptibilityTesting Twenty Fifth Information Supplement Clinical andLaboratory Standards Institute Wayne PA USA 2015

[29] E N Ndegwa CMMulei and S JMMunyua ldquoPrevalence ofmicroorganisms associatedwith udder infections in dairy goatson small-scale farms in Kenyardquo Journal of the South AfricanVeterinary Association vol 72 no 2 pp 97-98 2001

[30] M Pirzada K K Marhi A A Kamboh et al ldquoPrevalence ofsubclinical mastitis in dairy goats caused by bacterial speciesrdquoJournal of Animal Health and Production 2016

[31] A K Mishra N Sharma D D Singh et al ldquoPrevalence andbacterial etiology of subclinical mastitis in goats reared inorganized farmsrdquo Veterinary World vol 11 no 1 pp 20ndash242018

[32] K Hristov B Kashamov R Pepovich and B Nikolov ldquoRiskfactors influencing the prevalence of subclinical mastitis ingoatsrdquo Scientific Works Series C Veterinary Medicine no 1 pp53ndash57 2016

[33] T J N K Mbilu ldquoStatus of mastitis in lactating goats at SokoineUniversity of agriculture and neighbouring smallholder farmsin Morogoro Municipality Tanzaniardquo Livestock Research forRural Development vol 19 no 3 pp 54ndash60 2007

[34] L Makau Prevalence of mastitis and associated risk risk factorsin dairy goats in Machokos County Kenya University of NairobiThesis 2017

[35] E N Ndegwa C M Mulei and S J M Munyua ldquoTheprevalence of subclinical mastitis in dairy goats in KenyardquoJournal of the South African Veterinary Association vol 71 no1 pp 25ndash27 2000

[36] A Sanchez A Contreras and J Corrales ldquoParity as a riskfactor for caprine subclinical intramammary infectionrdquo SmallRuminant Research vol 31 no 3 pp 197ndash201 1999

[37] S R Salaberry A B Saidenberg E Zuniga et al ldquoVirulencefactors genes of Staphylococcus spp isolated from caprinesubclinical mastitisrdquo Microbial Pathogenesis vol 85 pp 35ndash392015

[38] S Dore M Liciardi S Amatiste et al ldquoSurvey on smallruminant bacterial mastitis in Italy 2013-2014rdquo Small RuminantResearch vol 141 pp 91ndash93 2016

6 Journal of Veterinary Medicine

Table 4 Resistance pattern of bacteria isolated from milk of goats with subclinical mastitis to 6 antibiotics

Percentage () of resistanceBacteria Chloramphenicol Penicillin G Tetracycline Norfloxacin Streptomycin GentamycinS aureus (n=8) 0 100 25 25 0 0CNS (n=10) 0 100 20 0 10 0Serratia (n=9) 33 100 22 0 0 0Klebsiella (n=8) 25 100 37 0 0 25Citrobacter (n=7) 57 100 57 0 0 0Enterobacter (n=6) 0 100 17 0 0 0E coli (n=4) 50 100 0 0 0 0n = 52

herd Monitoring somatic cell counts on a regular basis andfollow-up investigations give an indication of the success ofgood animal husbandry and hygiene practices It thereforeforms an integral part ofmastitis control strategies and assistsin diagnosis and treatment [45]

All of the tested bacteria were resistant to Penicillin GSimilar resistance was reported in India [10] and in Brazil[46] In Pakistan [43] resistance of bacteria to Penicillin Gwas found to be 5769The current study shows an increasedresistance pattern of bacteria to Penicillin G and this isprobably due to the long time and extensive use of Penicillinin the treatment of mastitis [10]

Most bacteria in the current study were sensitive toStreptomycin Gentamycin and Norfloxacin A study inNigeria [47] reported a high resistance of bacterial isolatesto Streptomycin This could have been due to the overuseof the antibiotic in the treatment of goat diseases in thestudy area The sensitivity of bacterial isolates in this studyto Streptomycin may be because the antibiotic is rarely usedin mastitis treatment in the study area Studies in Bangladeshreported high resistance of S aureus to Streptomycin [48] Inanother study in Ethiopia [49] varying degrees of resistanceof bacteria to Chloramphenicol Gentamycin and Strep-tomycin were reported These studies show that there aredifferences in sensitivity to antibiotics based on the regionand the usage of a particular antibiotic

Multidrug resistance of bacteria to Tetracycline andChloramphenicol found in this work is comparable to those[7 29 35] which reportedmultidrug resistance of the bacteriaisolated from dairy goats to tetracyclines The resistanceto beta-lactams and tetracyclines is due to the fact thatthese antibiotics are commonly used in treatment of variousbacterial diseases in dairy animals [50] Results of the currentstudy also found that most bacteria are still susceptible toantibiotics as reported by others [7 29 35] hence they canstill be used in the treatment of subclinical mastitis

5 Conclusion

The current study shows that dairy goats in Thika EastSubcounty of Kenya had high prevalence of subclinicalmastitis Since farmers are not wary of the occurrence ofthe subclinical disease they could be having major economiclosses through reduction in milk yield Farmers in the study

area should be encouraged to use California Mastitis Test toscreen for subclinical mastitis as it is highly sensitive and isaffordable The genus Staphylococci was the main etiologicalagent of contagious subclinical mastitis The study showedthat hygiene plays a big role in the occurrence of subclinicalmastitis hence the farmers should ensure good sanitationand maintain strict cleaning schedules for goat houses toreduce the occurrence of subclinical mastitis Most broad-spectrum antibiotics are still effective in treating subclinicalmastitis However Penicillin G should not be used in thetreatment of subclinical mastitis The extension workers inthe area should train farmers on improved animal husbandrypractices such as good housing maintenance of regularcleaning schedule and proper milking procedures

Data Availability

The raw data on prevalence of subclinical mastitis riskfactors and antibiotic sensitivity used to support the findingsof this study are available from the corresponding authorupon request

Conflicts of Interest

The authors declare that they have no financial or personalrelationships that may have inappropriately influenced themin writing this article

Acknowledgments

The authors are grateful to Institute of Basic Sciences Tech-nology and Innovation Pan-African University (PAUSTI)and Jomo Kenyatta University of Agriculture and Technol-ogy (JKUAT) for financially sponsoring this research andacknowledge the technical assistance provided by JKUATstaff including Dr Lewis Macharia and Mr Muthanga

References

[1] A Merz R Stephan and S Johler ldquoStaphylococcus aureusisolates from goat and sheep milk seem to be closely relatedand differ from isolates detected from bovine milkrdquo Frontiersin Microbiology vol 7 pp 1ndash7 2016

Journal of Veterinary Medicine 7

[2] D P Kateete U Kabugo H Baluku et al ldquoPrevalence andantimicrobial susceptibility patterns of bacteria from milk-men and cows with clinical mastitis in and around KampalaUgandardquo PLoS ONE vol 8 no 5 2013

[3] S E Idriss V Tancin V Foltys K Kirchnerova DTancinova and M Vrskova ldquoRelationship between mastitiscausative pathogens and somatic cell counts in dairy cowsrdquoPotravinarstvo vol 7 no 1 pp 33ndash38 2013

[4] M E Haque ldquoRapid detection of subclinical mastitis in dairycowrdquo Journal of Fisheries amp Livestock Production vol 03 no 012014

[5] G F W Haenlein ldquoGoat milk in human nutritionrdquo SmallRuminant Research vol 51 no 2 pp 155ndash163 2004

[6] C Boscos A Stefanakis C Alexopoulos and F SamartzildquoPrevalence of subclinical mastitis and influence of breedparity stage of lactation andmammary bacteriological status onCoulter counter counts and California mastitis test in the milkof Saanen and autochthonous Greek goatsrdquo Small RuminantResearch vol 21 no 2 pp 139ndash147 1996

[7] C M Mbindyo to Characterise Dairy Goats Production inMount Kenya Region Determinition of Prevalence and RiskFactors of Subclinical Mastitis and Antibiotic Sensitivity of TheIsolates University of NairobiThesis 2014

[8] G A Contreras and J M Rodrıguez ldquoMastitis Comparativeetiology and epidemiologyrdquo Journal of Mammary Gland Biologyand Neoplasia vol 16 no 4 pp 339ndash356 2011

[9] M Amin M Samad and A A Rahman ldquoBacterial pathogensand risk factors associatedwithmastitis in black bengal goats inbangladeshrdquo Bangladesh Journal of Veterinary Medicine vol 9no 2 pp 155ndash159 2013

[10] S Priya and S Ayodha ldquoBacterial and antibiogram studiesof milk samples of clinical mastitis in goatsrdquo IOSR Journal ofAgriculture and Veterinary Science vol 9 no 6 pp 33ndash35 2016

[11] A Arguello ldquoTrends in goat research a reviewrdquo Journal ofApplied Animal Research vol 39 no 4 pp 429ndash434 2011

[12] J K Shearer and B B Harris ldquoMastitis in Dairy goatsrdquo Journalof Animal Science pp 1ndash7 2003

[13] D Bergonier R de Cremoux R Rupp G Lagriffoul andX Berthelot ldquoMastitis of dairy small ruminantsrdquo VeterinaryResearch vol 34 no 5 pp 689ndash716 2003

[14] O Radostits C C Gay D C Blood and W HinchcliffeeVeterinary Medicine Textbook of the Diseases of Cattle SheepGoats and Horses London UK 9th edition 2000

[15] httpwwwaceseduurban[16] A Raikwar and P C Shukla ldquoDiagnosis of mastitis in dairy

goatsrdquo International Journal of Agricultural Sciences and Veteri-nary Medicine vol 3 no 1 pp 58ndash61 2015

[17] A Contreras J C Corrales D Sierra and J Marco ldquoPreva-lence and aetiology of non-clinical intramammary infection inMurciano-Granadina goatsrdquo Small Ruminant Research vol 17no 1 pp 71ndash78 1995

[18] A Bourabah A Ayad L Boukraa S M Hammoudi and HBenbarek ldquoPrevalence and etiology of subclinical mastitis ingoats of the Tiaret Region Algeriardquo Global Veterinaria vol 11no 5 pp 604ndash608 2013

[19] P Maisi and I Riipinen ldquoUse of california mastitis test jv-acetyl-120573-glucosaminidase and antitrypsin to diagnose caprinesubclinicalmastitisrdquo Journal of Dairy Research vol 55 no 3 pp309ndash314 1988

[20] O W Schalm E J Carroll and N C Jain Bovine Mastitis Leaand Febiger Philadelphia PA USA 1971

[21] C M Mbindyo and L Bebora ldquoA cross-sectional study onthe prevalence of subclinical mastitis and antimicrobial sus-ceptibility patterns of the bacterial isolates in milk samples ofsmallholder dairy goats in KenyardquoAmerican Journal of ResearchCommunication vol 2 no 8 2014

[22] S P Oliver and S E Murinda ldquoAntimicrobial resistance ofmastitis pathogensrdquo Veterinary Clinics of North America - FoodAnimal Practice vol 28 no 2 pp 165ndash185 2012

[23] J Barlow ldquoMastitis therapy and antimicrobial susceptibilityA multispecies review with a focus on antibiotic treatment ofmastitis in dairy cattlerdquo Journal of Mammary Gland Biology andNeoplasia vol 16 no 4 pp 383ndash407 2011

[24] M Thrusfield Veterinary Epidemiology Blackwell PublishingCompany 2007

[25] P J Quinn M E Carter B Markey and G R CarterClinical Veterinary Microbiology Mosby Publishing Company1st edition 1994

[26] M CheesbroughDistrict Laboratory Practice in Tropical Coun-tries Cambridge University Press Cambridge UK 1st edition2006

[27] D H Bergey N R Krieg and J G Holt Bergeyrsquos Manualof Systematic Bacteriology Wilkins Baltimore MD USA 6thedition 1984

[28] CLSI Performance Standards for Antimicrobial SusceptibilityTesting Twenty Fifth Information Supplement Clinical andLaboratory Standards Institute Wayne PA USA 2015

[29] E N Ndegwa CMMulei and S JMMunyua ldquoPrevalence ofmicroorganisms associatedwith udder infections in dairy goatson small-scale farms in Kenyardquo Journal of the South AfricanVeterinary Association vol 72 no 2 pp 97-98 2001

[30] M Pirzada K K Marhi A A Kamboh et al ldquoPrevalence ofsubclinical mastitis in dairy goats caused by bacterial speciesrdquoJournal of Animal Health and Production 2016

[31] A K Mishra N Sharma D D Singh et al ldquoPrevalence andbacterial etiology of subclinical mastitis in goats reared inorganized farmsrdquo Veterinary World vol 11 no 1 pp 20ndash242018

[32] K Hristov B Kashamov R Pepovich and B Nikolov ldquoRiskfactors influencing the prevalence of subclinical mastitis ingoatsrdquo Scientific Works Series C Veterinary Medicine no 1 pp53ndash57 2016

[33] T J N K Mbilu ldquoStatus of mastitis in lactating goats at SokoineUniversity of agriculture and neighbouring smallholder farmsin Morogoro Municipality Tanzaniardquo Livestock Research forRural Development vol 19 no 3 pp 54ndash60 2007

[34] L Makau Prevalence of mastitis and associated risk risk factorsin dairy goats in Machokos County Kenya University of NairobiThesis 2017

[35] E N Ndegwa C M Mulei and S J M Munyua ldquoTheprevalence of subclinical mastitis in dairy goats in KenyardquoJournal of the South African Veterinary Association vol 71 no1 pp 25ndash27 2000

[36] A Sanchez A Contreras and J Corrales ldquoParity as a riskfactor for caprine subclinical intramammary infectionrdquo SmallRuminant Research vol 31 no 3 pp 197ndash201 1999

[37] S R Salaberry A B Saidenberg E Zuniga et al ldquoVirulencefactors genes of Staphylococcus spp isolated from caprinesubclinical mastitisrdquo Microbial Pathogenesis vol 85 pp 35ndash392015

[38] S Dore M Liciardi S Amatiste et al ldquoSurvey on smallruminant bacterial mastitis in Italy 2013-2014rdquo Small RuminantResearch vol 141 pp 91ndash93 2016

Journal of Veterinary Medicine 7

[2] D P Kateete U Kabugo H Baluku et al ldquoPrevalence andantimicrobial susceptibility patterns of bacteria from milk-men and cows with clinical mastitis in and around KampalaUgandardquo PLoS ONE vol 8 no 5 2013

[3] S E Idriss V Tancin V Foltys K Kirchnerova DTancinova and M Vrskova ldquoRelationship between mastitiscausative pathogens and somatic cell counts in dairy cowsrdquoPotravinarstvo vol 7 no 1 pp 33ndash38 2013

[4] M E Haque ldquoRapid detection of subclinical mastitis in dairycowrdquo Journal of Fisheries amp Livestock Production vol 03 no 012014

[5] G F W Haenlein ldquoGoat milk in human nutritionrdquo SmallRuminant Research vol 51 no 2 pp 155ndash163 2004

[6] C Boscos A Stefanakis C Alexopoulos and F SamartzildquoPrevalence of subclinical mastitis and influence of breedparity stage of lactation andmammary bacteriological status onCoulter counter counts and California mastitis test in the milkof Saanen and autochthonous Greek goatsrdquo Small RuminantResearch vol 21 no 2 pp 139ndash147 1996

[7] C M Mbindyo to Characterise Dairy Goats Production inMount Kenya Region Determinition of Prevalence and RiskFactors of Subclinical Mastitis and Antibiotic Sensitivity of TheIsolates University of NairobiThesis 2014

[8] G A Contreras and J M Rodrıguez ldquoMastitis Comparativeetiology and epidemiologyrdquo Journal of Mammary Gland Biologyand Neoplasia vol 16 no 4 pp 339ndash356 2011

[9] M Amin M Samad and A A Rahman ldquoBacterial pathogensand risk factors associatedwithmastitis in black bengal goats inbangladeshrdquo Bangladesh Journal of Veterinary Medicine vol 9no 2 pp 155ndash159 2013

[10] S Priya and S Ayodha ldquoBacterial and antibiogram studiesof milk samples of clinical mastitis in goatsrdquo IOSR Journal ofAgriculture and Veterinary Science vol 9 no 6 pp 33ndash35 2016

[11] A Arguello ldquoTrends in goat research a reviewrdquo Journal ofApplied Animal Research vol 39 no 4 pp 429ndash434 2011

[12] J K Shearer and B B Harris ldquoMastitis in Dairy goatsrdquo Journalof Animal Science pp 1ndash7 2003

[13] D Bergonier R de Cremoux R Rupp G Lagriffoul andX Berthelot ldquoMastitis of dairy small ruminantsrdquo VeterinaryResearch vol 34 no 5 pp 689ndash716 2003

[14] O Radostits C C Gay D C Blood and W HinchcliffeeVeterinary Medicine Textbook of the Diseases of Cattle SheepGoats and Horses London UK 9th edition 2000

[15] httpwwwaceseduurban[16] A Raikwar and P C Shukla ldquoDiagnosis of mastitis in dairy

goatsrdquo International Journal of Agricultural Sciences and Veteri-nary Medicine vol 3 no 1 pp 58ndash61 2015

[17] A Contreras J C Corrales D Sierra and J Marco ldquoPreva-lence and aetiology of non-clinical intramammary infection inMurciano-Granadina goatsrdquo Small Ruminant Research vol 17no 1 pp 71ndash78 1995

[18] A Bourabah A Ayad L Boukraa S M Hammoudi and HBenbarek ldquoPrevalence and etiology of subclinical mastitis ingoats of the Tiaret Region Algeriardquo Global Veterinaria vol 11no 5 pp 604ndash608 2013

[19] P Maisi and I Riipinen ldquoUse of california mastitis test jv-acetyl-120573-glucosaminidase and antitrypsin to diagnose caprinesubclinicalmastitisrdquo Journal of Dairy Research vol 55 no 3 pp309ndash314 1988

[20] O W Schalm E J Carroll and N C Jain Bovine Mastitis Leaand Febiger Philadelphia PA USA 1971

[21] C M Mbindyo and L Bebora ldquoA cross-sectional study onthe prevalence of subclinical mastitis and antimicrobial sus-ceptibility patterns of the bacterial isolates in milk samples ofsmallholder dairy goats in KenyardquoAmerican Journal of ResearchCommunication vol 2 no 8 2014

[22] S P Oliver and S E Murinda ldquoAntimicrobial resistance ofmastitis pathogensrdquo Veterinary Clinics of North America - FoodAnimal Practice vol 28 no 2 pp 165ndash185 2012

[23] J Barlow ldquoMastitis therapy and antimicrobial susceptibilityA multispecies review with a focus on antibiotic treatment ofmastitis in dairy cattlerdquo Journal of Mammary Gland Biology andNeoplasia vol 16 no 4 pp 383ndash407 2011

[24] M Thrusfield Veterinary Epidemiology Blackwell PublishingCompany 2007

[25] P J Quinn M E Carter B Markey and G R CarterClinical Veterinary Microbiology Mosby Publishing Company1st edition 1994

[26] M CheesbroughDistrict Laboratory Practice in Tropical Coun-tries Cambridge University Press Cambridge UK 1st edition2006

[27] D H Bergey N R Krieg and J G Holt Bergeyrsquos Manualof Systematic Bacteriology Wilkins Baltimore MD USA 6thedition 1984

[28] CLSI Performance Standards for Antimicrobial SusceptibilityTesting Twenty Fifth Information Supplement Clinical andLaboratory Standards Institute Wayne PA USA 2015

[29] E N Ndegwa CMMulei and S JMMunyua ldquoPrevalence ofmicroorganisms associatedwith udder infections in dairy goatson small-scale farms in Kenyardquo Journal of the South AfricanVeterinary Association vol 72 no 2 pp 97-98 2001

[30] M Pirzada K K Marhi A A Kamboh et al ldquoPrevalence ofsubclinical mastitis in dairy goats caused by bacterial speciesrdquoJournal of Animal Health and Production 2016

[31] A K Mishra N Sharma D D Singh et al ldquoPrevalence andbacterial etiology of subclinical mastitis in goats reared inorganized farmsrdquo Veterinary World vol 11 no 1 pp 20ndash242018

[32] K Hristov B Kashamov R Pepovich and B Nikolov ldquoRiskfactors influencing the prevalence of subclinical mastitis ingoatsrdquo Scientific Works Series C Veterinary Medicine no 1 pp53ndash57 2016

[33] T J N K Mbilu ldquoStatus of mastitis in lactating goats at SokoineUniversity of agriculture and neighbouring smallholder farmsin Morogoro Municipality Tanzaniardquo Livestock Research forRural Development vol 19 no 3 pp 54ndash60 2007

[34] L Makau Prevalence of mastitis and associated risk risk factorsin dairy goats in Machokos County Kenya University of NairobiThesis 2017

[35] E N Ndegwa C M Mulei and S J M Munyua ldquoTheprevalence of subclinical mastitis in dairy goats in KenyardquoJournal of the South African Veterinary Association vol 71 no1 pp 25ndash27 2000

[36] A Sanchez A Contreras and J Corrales ldquoParity as a riskfactor for caprine subclinical intramammary infectionrdquo SmallRuminant Research vol 31 no 3 pp 197ndash201 1999

[37] S R Salaberry A B Saidenberg E Zuniga et al ldquoVirulencefactors genes of Staphylococcus spp isolated from caprinesubclinical mastitisrdquo Microbial Pathogenesis vol 85 pp 35ndash392015

[38] S Dore M Liciardi S Amatiste et al ldquoSurvey on smallruminant bacterial mastitis in Italy 2013-2014rdquo Small RuminantResearch vol 141 pp 91ndash93 2016

8 Journal of Veterinary Medicine

[39] A Contreras D Sierra A Sanchez et al ldquoMastitis in smallruminantsrdquo Small Ruminant Research vol 68 no 1-2 pp 145ndash153 2007

[40] P A Manser ldquoPrevalence causes and laboratory diagnosis ofsubclinical mastitis in the goatrdquo Veterinary Record vol 118 no20 pp 552ndash554 1986

[41] M Vyletelova O Hanus R Karpıskova and Z StrsquoastkovaldquoOccurrence and antimicrobial sensitivity in staphylococciisolated from goat sheep and cowrsquos milkrdquo Acta UniversitatisAgriculturae et Silviculturae Mendelianae Brunensis vol 59 no3 pp 209ndash214 2011

[42] S POliver and BAMitchell ldquoPrevalenceofmastitis pathogensin herds participating in a mastitis control programrdquo Journal ofDairy Science vol 67 no 10 pp 2436ndash2440 1984

[43] Z Ali G Muhammad T Ahmad et al ldquoPrevalence of Caprinesub-clinical mastitis its etiological agents and their sensitivityto antibiotics in indigenous breeds of kohatrdquo Pakistan Journalof Life and Social Sciences vol 8 no 1 pp 63ndash67 2010

[44] M J PaapeG RWiggans DD Bannerman et al ldquoMonitoringgoat and sheep milk somatic cell countsrdquo Small RuminantResearch vol 68 no 1-2 pp 114ndash125 2007

[45] R Pieterse and S D Todorov ldquoBacteriocins Exploring alterna-tives to antibiotics in mastitis treatmentrdquo Brazilian Journal ofMicrobiology vol 41 no 3 pp 542ndash562 2010

[46] E R Da Silva A P Siqueira J C D Martins W P B Ferreiraand N Da Silva ldquoIdentification and in vitro antimicrobialsusceptibility of Staphylococcus species isolated from goatmastitis in the Northeast of Brazilrdquo Small Ruminant Researchvol 55 no 1ndash3 pp 45ndash49 2004

[47] G O Egwu L T Zaria P A Onyeyili A G Ambali S SAdamu and M Birdling ldquoStudies on the microbiological floraof caprine mastitis and antibiotic inhibitory concentrations inNigeriardquo Small Ruminant Research vol 14 no 3 pp 233ndash2391994

[48] K M A Razi M B Rahman G H Flores-Gutierrez andM T Rahman ldquoPrevalence of caprine subclinical mastitis inMymensingh area Bangladesh and Characterization of Asso-ciated Bacterial Agents and the Risk Factorsrdquo Microbes andHealth vol 1 no 1 pp 1ndash5 June 2012

[49] A Wakwoya B Molla K Belihu J Kleer and G HildebrandtldquoA cross- sectional study on the prevalence antimicrobialsusceptibility patterns and associated bacterial pathogens ofgoat mastitisrdquo International Journal of Applied Research inVeterinary Medicine vol 4 no 2 2006

[50] E Pogurschi A Ciric C Zugrav and D Patrascu ldquoIdentifi-cation of Antibiotic Residues in Raw Milk Samples Comingfrom the Metropolitan Area of Bucharestrdquo Agriculture andAgricultural Science Procedia vol 6 pp 242ndash245 2015

Veterinary MedicineJournal of

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

International Journal of

Microbiology

Veterinary Medicine International

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

BioMed Research International

EcologyInternational Journal of

Hindawiwwwhindawicom Volume 2018

PsycheHindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

Biochemistry Research International

Hindawiwwwhindawicom

Applied ampEnvironmentalSoil Science

Volume 2018

Biotechnology Research International

Hindawiwwwhindawicom Volume 2018

Agronomy

Hindawiwwwhindawicom Volume 2018

International Journal of

Hindawiwwwhindawicom Volume 2018

Journal of Parasitology Research

Hindawiwwwhindawicom

International Journal of

Volume 2018

Zoology

GenomicsInternational Journal of

Hindawiwwwhindawicom Volume 2018

ArchaeaHindawiwwwhindawicom Volume 2018

Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawiwwwhindawicom

The Scientific World Journal

Volume 2018

Hindawiwwwhindawicom Volume 2018

Advances in

Virolog y

ScienticaHindawiwwwhindawicom Volume 2018

Cell BiologyInternational Journal of

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

Case Reports in Veterinary Medicine

Submit your manuscripts atwwwhindawicom

Veterinary MedicineJournal of

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

International Journal of

Microbiology

Veterinary Medicine International

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

BioMed Research International

EcologyInternational Journal of

Hindawiwwwhindawicom Volume 2018

PsycheHindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

Biochemistry Research International

Hindawiwwwhindawicom

Applied ampEnvironmentalSoil Science

Volume 2018

Biotechnology Research International

Hindawiwwwhindawicom Volume 2018

Agronomy

Hindawiwwwhindawicom Volume 2018

International Journal of

Hindawiwwwhindawicom Volume 2018

Journal of Parasitology Research

Hindawiwwwhindawicom

International Journal of

Volume 2018

Zoology

GenomicsInternational Journal of

Hindawiwwwhindawicom Volume 2018

ArchaeaHindawiwwwhindawicom Volume 2018

Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawiwwwhindawicom

The Scientific World Journal

Volume 2018

Hindawiwwwhindawicom Volume 2018

Advances in

Virolog y

ScienticaHindawiwwwhindawicom Volume 2018

Cell BiologyInternational Journal of

Hindawiwwwhindawicom Volume 2018

Hindawiwwwhindawicom Volume 2018

Case Reports in Veterinary Medicine

Submit your manuscripts atwwwhindawicom