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© 2008 The Authors Australian Veterinary Journal Volume 86, No 10, October 2008 Journal compilation © 2008 Australian Veterinary Association 371 EDITORIAL EDITORIAL Blackwell Publishing Asia In this issue Original articles Small animals Asymmetrical focal neurological deficits in dogs and cats with naturally occurring tick paralysis (Ixodes holocyclus): 27 cases (1999–2006) . In this retrospective study, 1 computer records were reviewed to assess the asymmetrical focal neurological deficits in all dogs and cats treated for tick paralysis ( Ixodes holocyclus ) over a 7-year period at a veterinary hospital in Newcastle, New South Wales. Neurological deficits were identified in 17 of 197 dogs and 10 of 89 cats. Deficits were not associated with season, severity of tick paralysis, breed, age, sex or body weight. Ticks were significantly more likely to be on the head of dogs and on the flank or back of cats, but other locations were similar between species. In animals with facial paralysis and anisocoria, the site of tick attachment was usually on the head or neck, and always ipsilateral to the facial paralysis. If there was only anisocoria, any one pupillary dimension was not related to the side of tick attachment. A new observation in one dog and one cat was the unilateral absence of cutaneous trunci reflex, and in these two cases, the site of tick attachment was the ipsilateral caudal axilla. Recovery for facial paralysis was a median of 13 days (but may persist for some weeks) compared with 2 days median recovery for generalised signs (P < 0.001). The authors conclude that if a patient presents with persistent unilateral facial paralysis, a recent history of tick paralysis should be considered. They conclude that tick paralysis should be considered after detection of an asymmetrical focal neurological deficit with lower motor neuron weakness, and that detection of one of these unilateral signs may assist in locating the tick. Molecular subtyping of feline immunodeficiency virus from cats in Melbourne Feline immunodeficiency virus (FIV), a lentivirus, is a common pathogen of domestic cats. Infection may be persistent and ultimately may cause immunosuppression, because opportunistic infections, neurological disease and lymphoma are reported in infected cats. This study 2 compared the genetic diversity of FIV from sick domestic cats in Melbourne with other FIV samples, including those in the FIV dual subtype vaccine. Results showed that all of the env gene sequences were clustered within subtype A, as previously shown. This is the first study to examine variability in the gag gene in Australian FIV. The authors note that further characterisation of the genetic diversity of FIV in other geographic areas may provide information about the evolution of the virus in Australia, which may be useful for vaccine studies. Cardiac troponin I is elevated in dogs and cats with azotaemic renal failure and in dogs with non-cardiac systemic disease Cardiac troponin I is a sensitive marker of myocardial injury. Elevated levels of cTnI are also seen in human patients with severe renal failure, diabetes, and non-specific critical illnesses, although the mechanism is uncertain. This cross-sectional study 3 measured cTnI in 39 dogs and 14 cats with azotaemic renal failure, with or without murmurs or hypertension, and 17 dogs with systemic illnesses without evidence of cardiac disease. Serum or heparinised plasma cTnI levels were increased above reference intervals in 70% of dogs and cats with azotaemic renal failure, and in 70% of the dogs with other systemic non-cardiac diseases. The levels did not correlate with the degree of azotaemia, hypertension, type of non-cardiac illness or the presence of murmurs. The authors conclude that as cTnI is often elevated in dogs and cats with systemic non-cardiac illness, such patients may have clinically inapparent myocardial injury or possibly altered elimination of cTnI. They conclude that cTnI has limited use as a diagnostic tool for primary cardiac disease or congestive heart failure. Production animals Financial modelling of the potential cost of ovine Johne’s disease and the benefit of vaccinating sheep flocks in southern New South Wales The on-farm cost of ovine Johne’s disease (OJD) should include primary treatment costs, including vaccination, as well as non- veterinary costs associated with altering or changing the enterprise mix on the farm. An enterprise gross margin (GM) model was developed to predict the on-farm financial impact of OJD for various sheep enterprises in Australia, 4 including estimating the benefits and costs of control through the use of the Gudair™ vaccine. Data were taken from a 3-year observational study using sheep from 12 OJD-infected flocks of between 3500 and 20,000 sheep from southern New South Wales. The owners estimated at least 5% OJD mortality at the start of the study. The model compared non-infected, infected (status quo) and infected (vaccination) disease scenarios in high, medium, low and at-risk disease categories. Results showed that vaccination breakeven points occur within 2 to 3 years for breeding enterprises if OJD mortalities were high, and within 7 years for a Merino ewe enterprise if OJD mortalities were low. In the at-risk category in which there were no OJD mortalities, a vaccination breakeven point was never reached. The GM model is designed to process one enterprise type at a time for individual farm planning and control. The authors conclude that it is a useful decision-making tool that estimates the total and the avoidable on-farm costs of OJD, including the benefits of vaccination.
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Transcript of In this issue
© 2008 The Authors
Australian Veterinary Journal
Volume 86, No 10, October 2008Journal compilation © 2008 Australian Veterinary Association
371
ED
ITO
RIA
L
EDITORIAL
Blackwell Publishing Asia
In this issue
Original articles
Small animals
Asymmetrical focal neurological deficits in dogs and cats withnaturally occurring tick paralysis
(Ixodes holocyclus):
27 cases(1999–2006)
.In this retrospective study,
1
computer records were reviewed toassess the asymmetrical focal neurological deficits in all dogs andcats treated for tick paralysis (
Ixodes holocyclus
) over a 7-yearperiod at a veterinary hospital in Newcastle, New South Wales.Neurological deficits were identified in 17 of 197 dogs and 10 of89 cats.
Deficits were not associated with season, severity of tick paralysis,breed, age, sex or body weight. Ticks were significantly morelikely to be on the head of dogs and on the flank or back of cats,but other locations were similar between species.
In animals with facial paralysis and anisocoria, the site of tickattachment was usually on the head or neck, and always ipsilateralto the facial paralysis. If there was only anisocoria, any onepupillary dimension was not related to the side of tick attachment.A new observation in one dog and one cat was the unilateralabsence of cutaneous trunci reflex, and in these two cases, the siteof tick attachment was the ipsilateral caudal axilla. Recovery forfacial paralysis was a median of 13 days (but may persist for someweeks) compared with 2 days median recovery for generalisedsigns (P < 0.001). The authors conclude that if a patient presentswith persistent unilateral facial paralysis, a recent history of tickparalysis should be considered. They conclude that tick paralysisshould be considered after detection of an asymmetrical focalneurological deficit with lower motor neuron weakness, and thatdetection of one of these unilateral signs may assist in locatingthe tick.
Molecular subtyping of feline immunodeficiency virus from cats in Melbourne
Feline immunodeficiency virus (FIV), a lentivirus, is a commonpathogen of domestic cats. Infection may be persistent andultimately may cause immunosuppression, because opportunisticinfections, neurological disease and lymphoma are reported ininfected cats. This study
2
compared the genetic diversity ofFIV from sick domestic cats in Melbourne with other FIVsamples, including those in the FIV dual subtype vaccine. Resultsshowed that all of the env gene sequences were clustered withinsubtype A, as previously shown. This is the first study to examinevariability in the gag gene in Australian FIV. The authors notethat further characterisation of the genetic diversity of FIV inother geographic areas may provide information about theevolution of the virus in Australia, which may be useful forvaccine studies.
Cardiac troponin I is elevated in dogs and cats with azotaemic renal failure and in dogs with non-cardiac systemic disease
Cardiac troponin I is a sensitive marker of myocardial injury.Elevated levels of cTnI are also seen in human patients withsevere renal failure, diabetes, and non-specific critical illnesses,although the mechanism is uncertain. This cross-sectional study
3
measured cTnI in 39 dogs and 14 cats with azotaemic renalfailure, with or without murmurs or hypertension, and 17 dogswith systemic illnesses without evidence of cardiac disease. Serumor heparinised plasma cTnI levels were increased above referenceintervals in 70% of dogs and cats with azotaemic renal failure,and in 70% of the dogs with other systemic non-cardiac diseases.The levels did not correlate with the degree of azotaemia,hypertension, type of non-cardiac illness or the presence ofmurmurs. The authors conclude that as cTnI is often elevated indogs and cats with systemic non-cardiac illness, such patientsmay have clinically inapparent myocardial injury or possiblyaltered elimination of cTnI. They conclude that cTnI has limiteduse as a diagnostic tool for primary cardiac disease or congestiveheart failure.
Production animals
Financial modelling of the potential cost of ovine Johne’s disease and the benefit of vaccinating sheep flocks in southern New South Wales
The on-farm cost of ovine Johne’s disease (OJD) should includeprimary treatment costs, including vaccination, as well as non-veterinary costs associated with altering or changing the enterprisemix on the farm. An enterprise gross margin (GM) model wasdeveloped to predict the on-farm financial impact of OJD forvarious sheep enterprises in Australia,
4
including estimating thebenefits and costs of control through the use of the Gudair™vaccine. Data were taken from a 3-year observational study usingsheep from 12 OJD-infected flocks of between 3500 and 20,000sheep from southern New South Wales. The owners estimated atleast 5% OJD mortality at the start of the study. The modelcompared non-infected, infected (status quo) and infected(vaccination) disease scenarios in high, medium, low and at-riskdisease categories.
Results showed that vaccination breakeven points occur within 2to 3 years for breeding enterprises if OJD mortalities were high,and within 7 years for a Merino ewe enterprise if OJD mortalitieswere low. In the at-risk category in which there were no OJDmortalities, a vaccination breakeven point was never reached.The GM model is designed to process one enterprise type at a timefor individual farm planning and control. The authors concludethat it is a useful decision-making tool that estimates the totaland the avoidable on-farm costs of OJD, including the benefitsof vaccination.
(01)avj_353.fm Page 371 Thursday, September 18, 2008 1:10 PM
Australian Veterinary Journal
Volume 86, No 10, October 2008 © 2008 The AuthorsJournal compilation © 2008 Australian Veterinary Association
ED
ITO
RIA
L
EDITORIAL
372
Equine
Surgical management of sand colic impactions in horses: a retrospective study of 41 cases
The aim of this retrospective review of medical records
5
was toidentify factors associated with survival in horses needingabdominal surgery for sand colic, which is diagnosed when sandis found to be the cause of impaction of the gastrointestinaltract during surgical exploration. A total of 41 horses were treatedat the Veterinary Teaching Hospital in Koret School inJerusalem. The most common presenting signs were abdominalpain, abdominal distension and diarrhoea. Ventral midlinelaparotomy was carried out with the horses in dorsalrecumbency. All patients underwent enterotomy at the greatercurvature of the pelvic flexure to evacuate the contents of thescending colon using a non-sterile garden hose. Sand impactionoccurred in multiple locations in one-third of the horses, andconcurrent pathology was detected in half of the horses,although it was unclear whether this was related to the sandcolic. Four horses were euthanased during surgery, and of thosethat recovered from surgery, 35 were discharged from hospitaland all were still alive a year later. Three horses showed signs ofabdominal pain a few months after surgery and one developedan incision hernia.
The authors conclude that early surgical exploration is neededfor horses in cases where large amounts of sand are suspected.
Wildlife & zoos
Mitogen-induced responses in lymphocytes from platypus, the Tasmanian devil and the eastern barred bandicoot
The platypus (
Ornithorhynchus anatinus
), the Tasmanian devil(
Sarcophilus harrisi
) and the eastern barred bandicoot (
Peramelesgunni
) are currently at serious risk of population decline orextinction from fatal diseases, but little is known about theirbasic immune function. Recent studies have used molecularbiology techniques to look at T-cell receptor composition andimmunoglobulins, but this is not of immediate practical valuefor assessing the health of the immune system. The lymphocyteproliferation assay measures the cell-mediated response, which isa major part of the defence against infection, and so reflects theimmune capability of the animals. This preliminary study
6
usedperipheral blood mononuclear cells from blood samples from8 platypuses, 6 devils and 7 bandicoots. Cells were used forlymphocyte proliferation assays using the common mitogensphytohaemagglutinin (PHA), concanavalin A (ConA), lipopoly-saccharide (LPS) and pokeweed mitogen (PWM).
This paper reports the normal cellular response of three nativespecies to a range of commonly used mitogens. Tasmanian devilsand bandicoots had greater responses than platypuses, although
variability between individual animals was high. The methodwill be used further to test animals with disease to assess theeffect of infection on the cellular response.
Case report
Small animals
Use of continuous positive airway pressure in the acute management of laryngeal paralysis in a cat
Continuous positive airway pressure (CPAP) is used in humansfor management of obstructive sleep apnoea syndrome. It acts asa pneumatic splint and prevents the pharynx from collapsing. Ithas not been widely used in animals. This case report
7
concernsa brachycephalic Persian cat with previously undiagnosedlaryngeal paralysis that developed acute upper respiratory tractobstruction on recovery from anaesthesia. Visualisation of thelarynx at the time showed adduction of both vocal folds and theairway closed almost completely during inspiration. CPAP wasdelivered via a facial mask to restore airway patency, andbreathing improved after the mask was applied. CPAP wascontinued for approximately 20 minutes until the cat was able tobreath unaided. The authors consider that the original cause wasa combination of the brachycephalic conformation and laryngealparalysis that was probably idiopathic. They note that CPAPmay be an additional method of managing animals that are inacute respiratory distress following laryngeal paralysis.
References
1. Holland CT. Asymmetrical focal neurological deficits in dogs and cats with nat-urally occurring tick paralysis (
Ixodes holocyclus
): 27 cases (1999–2006).
AustVet J
2008;86:377–384.2. Iwata D, Holloway SA. Molecular subtyping of feline immunodeficiency virusfrom cats in Melbourne.
Aust Vet J
2008;86:385–389.3. Porciello F, Rishniw M, Herndon WE, Birettoni F, Antognoni MT, Simpson KW.Cardiac troponin I is elevated in dogs and cats with azotaemic renal failure and indogs with non-cardiac systemic disease.
Aust Vet J
2008;86:390–394.4. Bush RD, Windsor PA, Toribio JA, Webster SR. Financial modelling of thepotential cost of ovine Johne’s disease and the benefit of vaccinating sheepflocks in southern New South Wales.
Aust Vet J
2008;86:398–403.5. Granot N, Milgram J, Bdolah-Abram T, Shemesh I, Steinman A. Surgical man-agement of sand colic impactions in horses: a retrospective study of 41 cases.
Aust Vet J
2008;86:404–407.6. Stewart N, Bettiol S, Kreiss A, Fox N, Woods G. Mitogen-induced responses inlymphocytes from platypus, the Tasmanian devil and the eastern barred bandicoot.
Aust Vet J
2008;86:408–413.7. Ticehurst K, Zaki S, Hunt GB, MacPherson C, Nicholson H. Use of continuouspositive airway pressure in the acute management of laryngeal paralysis in a cat.
Aust Vet J
2008;86:395–397.
(Accepted for publication xx xxxx 2008)
Anne JacksonEditor in Chief
doi: 10.1111/j.1751-0813.2008.00353.x
(01)avj_353.fm Page 372 Thursday, September 18, 2008 1:10 PM
