Coccidiosis is an intestinal disease that affects several different animal species including domestic animals and humans.

 Eimeria and Isosporaare the two genera that are often referred to as "coccidia.“

Coccidia is host specific & no cross immunitybetween species.

Are unicellular parasites and pandemic in occurance..

ETIOLOGYKingdom : ProtistaSubkingdom : ProtozoaPhylum : ApicomplexaClass : SporozoaSubclass : CoccidiaOrder : EucoccidiidaSuborder : EimerinaFamily : EimeriidaeGenera : Eimeria

FACTSHISTORYEimeria species was one of the first protists

ever visualized when Antoni van Leeuwenhoek saw what surely were oocysts of Eimeria steidai  in the bile of a rabbit in 1674.

MORPHOLOGYCoccidia contains structures like oocyst-

sporulated and nonsporulated,trophozoites and merozoites.

Schizonts present are of two types-giant schizonts & epithelial schizonts..

STAGES OF EIMERIA

EPIDEMIOLOGYPandemic in occurance.Prevalence of infection & incidence of

clinical disease is age related.In housed diary cattle prevalence is 46%-calves,43%-yearlings,16%-adultcows.

Seasonal variation of disease is reported in many regions..

CALVES-winter coccidiosis is prevalent in calves in Canada due to prolonged cold period, as cold weather act as stressor to precipitate clinical disease..

Postweaning coccidiosis occurs due to immunosupressive effect of weaning& dietary diseases in Australia.

Overcrowding, dirty & wet conditions cause disease in diary calves, due to faecal contamination of feed.

LAMBS-common disease in household flocks due to feedlotsituation,overcrowding & other stressors present.

GOATS-under intensive management conditions prevalence is high as 100%.

Major source of pasture contamination is kids & weaned kids have high oocyst counts.

PIGS-morbidity rates are variable & casefatality rate is 20% in porcine coccidiosis.Have repeated epidemics of neonatal diarrhoea.

Prevalence more when piglets raised on solid cement floors..

MORBIDITY &CASEFATALITYMost species infection rate is high,rate of clinical disease is 5-10%;but epidemics affects 80%.

Casefatality rate in calves is high with winter coccidiosis accompanied by nervous signs.

Subclinical infection is common in lambs on pasture. Case fatality rate in lambs infected with Eimeria ninakohlyakinovae of 50%.

Pigs infected with Isospora suis have reduced body wt at 21day age & affects sow productivity index..

TRANSMITTED BYIngestion of contaminated feed & water.

Faeces of clinically affected or carrier animals. Licking of haircoat contaminated with infected faeces.

Ingestion of sporulated oocysts results in infection.

Overcrowding of pastured animals on irrigated pastures .

Possible sources of infective oocysts for lambs before 4 weeks of age:

a) Oocysts surviving in old faecal contamination of lambing area.

b)Fresh oocysts constantly shed by ewes.

c)Fresh oocyst shed by other lambs..

RISK FACTORSANIMAL RISK FACTORS Eimeria species specific age resistance:acute coccidiosis common in young animals or at any age due to intercurrent disease or inclement weather.

Nutritinal status: risk factor for clinical coccidiosis ;early weaned lambs,planes of nutrition

ENVIRONMENT & MANAGEMENT RISK FACTORS

Oral exposure of large numbers of sporulated oocysts to non-immune animals.

Grazing calves for the first time on permanent pastures leads to clinical coccidiosis.

Intensity of infection is directly related to number of oocyst in environment & ingested by animals.

Production system influences development of subclinical & clinical coccidiosis.

PATHOGEN RISK FACTORSSingle species of coccidia may be major pathogen;others predisposes to disease.

In sheep & goats prevalence of multiple species as high as 95% & 85%.

Moist, temperate or cool conditions favor sporulation.

IMMUNE MECHANISMSImmunity against intestinal coccidia consists of both cellular & humoral components.

Cellular immunity is more important in resistance against reinfection.

In lambs immunity induced by the first infection provides resistance to reinfections.

Immunity to range of species of coccidia is boosted by frequent reinfections.

Young lambs are relatively resistant to infection with a mixture of pathogenic species of coccidia.

In field conditions, coccidiosis in cattle is immunosupressive & increase the susceptibility to other infections.

PATHOGENESIS Ingestion of sporulated oocyst Schizogony in villi,bileducts.. Binaryfission of trophozoites Merozoites invades host cell

Microgametocyte & Megagametocyte Oocyst formation Excret ion of oocyst in faeces In natural external environment,oocysts remain viable and infective as 49 days up to 86 weeks, dependent upon the species

ATT

CATTLE LIFE CYCLE

SHEEP &

GOAT

CLINICAL SIGNSCATTLE-E.bovis & E.zuerniiMainly 3 weeks -6months of age. Most common sign is a watery

diarrhoea,accompanied by straining, mucous and blood.

Depression, loss of appetite, weight loss, tenesmus, rarely with diarrhoea in milk-fed calves, dehydration. Death is rare.

Sub-clinical infection is very common, up to 95% .Nervous signs seen with hyperesthesia,nystagmus

& mortality rates80-90% in calves.

Species location oocyst structure

sporocyst

sporulation

prepatentperiod

Eimeria alabamesis

Small intestine,caecum

Ovoid,pyriform

Micropyle & micropylarcap

Elongated

8-10 days

6-11days

E. zuernii Small and large intestine

Spherical

Micropyle absent

Elongated

3-4days

15-17days

E.auburnensis

Lower 3rd of small intestine

Ovoid Micropylarcap absent

Elongated

3-4days

16-24days

E. bovis Small intestine & caecum

Ovoid Micropyle

Elongated

2-4days

15-21days

E.ellipsoidalis

Small intestine

Ellipsoid

Micropyle

Elongated

3-4days

8-13days

E.bareillyi Upperpart of jejunum

Pyriform

Micropyle

Banana

3-4 days

12-13dayss

GOATSGOATEimeri

a arloingi

Intestine

Ellipsoidal

Micropylarcap

Ovoid 1-4days

14-17days

E.christenseni

Small intestine

Ovoid Micropylarcap

Ovoid 2-6days

14-23days

E.ninakohylakinovae

Small intestine & caecum

Ovoid Micropyle

Ovoid 1-4days

E.caprina

Species most commonly reported from kerela

E.apsheronica

Small intestine

Ovoid Micropyle

Pyriform

14-17dayss

E.christenseni.E.ninakohlyakinovae E.arloingi pathogenic

Sudden onset of severe diarrhea with foul smelling, fluid faeces often containing mucus and blood. The perineum and tail are usually stained with blood-stained, possible rectal prolapse.

Inappetance ,anemia with pale nucosa , dyspnoea In kids raised and fed in crowded conditions, the

symptoms over a 1-3 week period include inferior growth rates, inappetence, recumbency, emaciation and death.

There is usually a lag of 14-18 days between a massive ingestion and the presence of oocytes in the faeces.

SHEEPSHEEPEimeria

ahsataSmall intestine

Ellipsoidal

Micropylar cap

Elongated

36-72hrs

18-20days

E.ovina Small intestine

Ellipsoidal

Micropylarcap

Elongated

2-4days

19-20days

E.parva Small intestine

Spherical

Ellipsoidal

2-3days

16-17days

E.gilruthi

Connective tissue mucosa of abomasum.Schizonts globoidal.

E.crandallis

Small intestine

Ellipsoidal

Micropylar cap

Ovoid 1-3days

E.faurei

Small intestine

Ovoid Micropyle

Ovoid 1-4dayss

E.ovinoidalis,E.ovina,E.parva & E.ahsata

Lambs at 3-8 weeks most frequently affected, as maternal immunity declines.

Inferior growth rates,diarrhoea with or without blood,recumbency,emaciation etc.

Death within 1-3 weeks noted

PIGSPIGEimeria

deblieckiSmall intestine

Ovoid Micropyle absent

ovoid 10days

7days

E.scabra Small intestine

Ellipsoidal

Micropyle

Ovoid 9-12days

9days

E.neodebliecki

Small intestine

Ellipsoidal

Steidae body

Elongated

13days

10days

E.polita Small intestine

Ellipsoidal

Stiedae body

Smooth

8-9days

7-8days

E.perminuta

Small intestine

Spherical

Steidae body

Elongated

7-9days

Isospora suis

Small intestine

Spherical

Ellipsoidal

4-5dayss

• E.debliecki & E. scabra pathogenic.• Scour in piglets from 10-20 days old.• Anorexia & depression,faeces will be yellow, watery & foamy• Isospora suis produces diarrhoea, villous atrophy & necrosis of intestinal epithelium.• It has 3 asexual,one sexual & intraintestinal multiplication cycles..

HORSES & CAMELHORSES AND CAMELEimeria

leuckarti

Small intestine

Ovoid

Micropylarcap absent

Elongated

15-41days

Eimeria cameli

Small intestine

Truncate

Steidae body absent

Elongated

E.dromedarii

Small intestine

Ovoid

Steidae body absent

Spherical

15-17days

E.rajasthani

Small intestine

Ovoid

Steidae body

Ovoid 7dayss

In horses only one species pathogenic- E.leuckarti .

Common in weaned foals.Diarrhoea of prolong duration & acute massive intestinal haemorrhage; which results in rapid death.

CLINICAL PATHOLOGYStages of

coccidia in mucosal smearss

NECROPSY FINDINGSCattle- congestion, haemorrhage & thickening of mucosa of caecum, colon,rectum & ileum, ridges in mucosa

Small white cyst bodies formed by schizonts visible on tips of villi of treminal ileum.

Ulceration or sloughing of mucosa.Bloodstained faeces present in lumen of large intestine.

Histologically denudation of epithelium & merozoites observed in some cells.

In piglets small intestine is usually flaccid with fibrinonecrotic enteritis.

In sheeps severe diffuse crypt hyperplasia in small & large intestines.

In infections with E. gilruthi numerous nodules in abomasum.

DIAGNOSIS..Faecal smear examination-segments of jejunum, ileum and colon.

Histologically –formalin fixed duodenum,jejunum,ileum, caecum & colon.

Merozoites in intestinal tissues.Serological methods- PCR detection ,autofluorescence microscopy(10 oocysts/gm).

DIFFERENTIAL DIAGNOSIS CALVES –Clostridium perfringens type c,colibacillosis,rotavirus & coronaviru diarrhoea.

LAMBS-enterotoxemia,salmonellosis & helminthiosis.

PIGLETS-enterotoxemia,colibacillosis & transmissible gastroenteritis .

FOALS-salmonellosis,Clostridium perfringens type b enterotoxemia, foal heart diaarhoea & rotavirus diarrhoea..

TREATMENTIsolation of clinically affected animals.Supportive oral & parenteral fluid therapy

especially those affected with nervous coccidiosis.

Sulfonamide therapy parentrally is effective in acute clinical coccidiosis in calves.

Amprolium beneficial effects in terms of body weight gain .

In piglets symmetrical triazintriones effective against sexual & asexual stages of Isospora suis

Chemotherapeutic agent

Treatment Prevention

Sulfadimidine Calves & lambs:140mg/kg BW orally daily for 3 days individually.

Calves in feed-35mg/kg Bwfor 15 daysLambs –daily dose 25mg/kg BW for one week.

Amprolium Calves –individual dose @ 10mg/kg BW daily for 5 days.

Calves –in feed @ 5mg/kg BW for 21 days.Lambs –in feed 50mg/kg BW for 21 days

Monensin Lambs -2mg/kg BW daily for 20 days

Calves -33g/tonne for 31 daysLambs -25-100mg/kg feed from weaning until marketing.

PREVENTION & CONTROLMANAGEMENT OF ENVIRONMENT- overcrowding of animals should be avoided. Lambing & calving areas should be well drained. Adequate hygiene measures to be adopted. Feed & water troughs should be placed at a

height. Frequent rotation of pastures is advised.COCCIDISTATS Have a depressant effect on early first stage

schizonts. Allow development of effective immunity.

Ionophore s–monensin coccidiostat & growth promotant in cattle , sheep & goats.Reduce the oocyst output of ewes & lambs when fed before & after lambing.

Lasalocid @ a rate of 40mg/kg to dairy calves at 3 days of age to 12 weeks of age reduce oocyst in faeces.

Decoquinate in feed @ rate of 0.5 -1mg/kgBW supressed oocyst production.

Toltrazuril at 20mg/kg BW as single dose almost prevent coccidiosis.

VACCINES…There is no report of vaccines successfully developed against coccidiosis in animals.

Due to the lack of understanding of immune mechanisms to primary & secondary infection & capacity of protozoa to evade the host immunity are the obstacles…..