bluuebunny/crossref_metadata_2025 huggingface dataset:
Epidemiology and diagnosis of subclinical iodine deficiency in crossbred cattle of Punjab
Authors: RANDHAWA CS , RANDHAWA SS
Published: March 2008

Objective To determine the prevalence of iodine deficiency in crossbred cows (taurus x indicus) of Punjab and to assess the diagnostic value of the plasma concentrations of thyroid hormones, total cholesterol and free fatty acids in iodine deficiency. The efficacy of ethiodised oil, as a long‐term supplement of iodine, was also evaluated.

Procedures Base‐line survey of iodine status was conducted by measuring plasma inorganic iodine (PII) concentration in 48 crossbred cows from 31 dairy units. Concentrations of plasma triiodothyronine (T3), thyroxine (T4), total cholesterol and free fatty acids were compared between iodine deficient and normal cows. Circulating T4 and T3 concentrations were also determined before and after injection of ethiodised oil in cows with low PII levels.

Results The mean prevalence of iodine deficiency was 35.9% and showed considerable geographical variation from 0 to 86% within Punjab. Cardinal clinical signs of iodine deficiency were absent and basal plasma T3 and T4 concentrations and their ratio did not differ between deficient and control cows. Activity of circulating T4 and T4:T3 ratio increased in response to ethiodised oil injection and persisted beyond 70 days after injection.

Conclusion Asymptomatic iodine deficiency is prevalent in crossbred cows of Punjab and response to iodine supplementation is the most reliable index of thyroid dysfunction associated with iodine deprivation. The results of this study also support the view that injection of 1 mL of 78% ethiodised oil can prevent iodine deficiency for more than 70 days.
Risk factors for dystocia in farmed red deer (Cervus elaphus)
Authors: AUDIGÉ L , WILSON PR , MORRIS RS
Published: March 2008

Objective To analyse data from a study of deer herd health and productivity to identify potential risk factors for the occurrence of dystocia.

Design A 2‐year longitudinal observational study of 14 red deer farms was carried out in New Zealand. About 2700 hinds were monitored each year for individual characteristics including body condition score (BCS), and reproductive performance. Grazing and calving management practices were recorded. During calving, farmers recorded calving difficulties (dystocia) that needed human assistance or caused the death of the hind. Risk factors potentially affecting the occurrence of dystocia were identified and analysed by multivariable statistical techniques.

Results The percentage of hinds with dystocia was 0.52% (95% CI 0.32 to 0.78). Hinds with a post‐winter BCS over 3.5 were 2.7 times as likely to experience dystocia as hinds scoring 3.5 or less. Given the same BCS class, bodyweight gain in late pregnancy was associated with an increased risk of dystocia. Grazing steep paddocks in the last trimester of pregnancy decreased the risk of dystocia in hinds with a BCS over 3.5.

Conclusions The risk of dystocia on red deer farms may be reduced if key individual animal, management and environmental factors are optimal.
Granulosa cell tumour in two speyed bitches
Authors: SIVACOLUNDHU RK , HARA AJ , READ RA
Published: March 2008

Granulosa cell tumours are uncommon ovarian tumours in the bitch and are rare in speyed bitches. This case report describes two cases of granulosa cell tumour in bitches that were speyed at less than 1‐year‐of‐age. Both animals presented with persistent vulval bleeding. Although the majority of granulosa cell tumours are large enough to be palpated by the time of presentation, both tumours were relatively small. Granulosa cell tumour is a possible complication of incomplete ovarian excision at the time of ovariohysterectomy. In cases of granulosa cell tumour in previously speyed bitches, with no evidence of metastases, tumour resection should be curative. Ovaries should be double‐checked at the initial ovariohysterectomy to ensure all normal ovarian tissue has been excised.
Diagnosis and management of cor triatriatum dexter in a Pyrenean Mountain Dog and an Akita Inu
Authors: MITTEN RW , EDWARDS GA , RISHNIW M
Published: March 2008

Cor Triatriatum Dexter is a rare, congenital cardiac defect in which the right atrium is partitioned into two compartments, effectively creating a triatrial heart. The clinical signs exhibited by the patient usually relate to impeded venous return via the caudal vena cava. The two dogs in this report both displayed ascites from a young age and grew poorly. In both cases the diagnosis was made during echocardiographic examination and was confirmed by angiography. Both dogs were successfully treated by resection of the partitioning membrane within the right atrium, using hypothermia and inflow occlusion to achieve a clear surgical field. Both dogs recovered well, their clinical signs resolved and they have grown to normal adult size.
Feline polycystic kidney disease in Persian and other cats: a prospective study using ultrasonography
Authors: BECK C , LAVELLE RB
Published: March 2008

ObjectiveTo determine the prevalence of feline polycystic kidney disease in Persian cats presented to the University of Melbourne Veterinary Clinic and Hospital between February and August 1999.

DesignA prospective clinical study using client owned animals was performed.

ProcedureTwo hundred and fifty Persian cats, ranging in age from 13 weeks to 10 years, were presented to the University of Melbourne Veterinary Clinic and Hospital for ultrasound examination of both kidneys. The cats were placed in dorsal and lateral recumbency and alcohol and ultrasonic coupling gel were applied to the skin. The kidneys were examined ultrasonographically in longitudinal, sagittal and transverse planes. Results were recorded for each cat at the time of examination as either negative or positive for PKD. In addition 14 Exotics (short‐haired Persians), 4 Ragdolls and 3 British Short‐Hair cats were examined.

ResultsForty five percent of Persian cats examined were found to be positive for feline polycystic kidney disease on the basis of presence of anechoic cysts within the renal parenchyma. These cats ranged in age from 13 weeks to 10 years. Fifty per cent of the Exotic cats were positive for polycystic kidney disease whereas all Ragdolls and British Short Hairs were negative for the disease. Only one positive cat was reported to be showing clinical signs of renal disease.

ConclusionThe prevalence of feline polycystic disease in Persian cats presented to the University of Melbourne between February and August 1999 was 45%. Exotic cats were found to have the slightly higher incidence of 50%.
Combined xylazine and ketamine as an analgesic regimen in sheep
Authors: HUGHAN SC , LOOSE JM , CADDY DJ , CANNY BJ , TILBROOK AJ , YOUNG IR
Published: March 2008

ObjectiveTo determine whether low dose xylazine with ketamine reduces the concentrations of cortisol and prolactin in sheep postoperatively and to characterise the effects of the drugs on behaviour during recovery.

DesignAnalysis of variance was used to compare the effects of anaesthesia, surgery and combined ketamine/ xylazine treatment on the plasma cortisol and prolactin concentrations and on behavioural variables in pregnant ewes subjected to abdominal surgery.

ProcedureTwelve ewes were randomly assigned to receive either ketamine/xylazine or placebo in association with anaesthesia and surgery. Both groups of ewes underwent anaesthesia alone followed a week later by anaesthesia with laparotomy and hysterotomy. Plasma cortisol and prolactin concentrations were assayed during these procedures and for 5 days afterwards. Behavioural observations were made remotely during recovery from anaesthesia and anaesthesia plus surgery.

ResultsThe concentrations of cortisol in the plasma of pregnant ewes undergoing surgery were increased by preoperative handling and the onset of thiopentone/halothane anaesthesia, with a further increase during surgery (P = 0.033). Cortisol concentrations decreased over the first four postoperative hours (P = 0.029) and were normal by 24 h. The drug treatment did not affect the immediate responses of ewes to anaesthesia or surgery, although treated ewes had lower cortisol concentrations than saline‐treated controls over the first five postoperative days (P = 0.018).

Prolactin concentrations increased in response to anaesthesia (P = 0.047), but were not affected by surgery or the drug treatment.

Drug‐treated ewes had prolonged sleeping time after surgery (P = 0.002), but they took no longer to stand than saline‐treated controls and required fewer attempts to stand successfully (P = 0.025).

ConclusionAt the doses used, ketamine and xylazine did not mitigate the immediate endocrine consequences of surgery but the behavioural data provide a basis for further investigations that may lead to improvements in analgesic treatments.
BOOK REVIEW
Authors: Thomas PGA
Published: March 2008

Arthur's Veterinary Reproduction and Obstetrics, 8th edn. Noakes DE, Parkinson TJ, England GCW and Arthur GH, editors, Harcourt Australia, Marrickville, 2001, 868 pages. Price $288.75. ISBN 0 7020 2556 9.
Babesia gibsoni infection in three dogs in Victoria
Authors: MUHLNICKEL CJ , JEFFERIES R , MORGAN‐RYAN UM , IRWIN PJ
Published: March 2008

Small intraerythrocytic parasites were observed in the blood of three related male American Pit Bull Terriers. Two of the dogs, both less than 1‐year‐old, were anaemic at the time of initial examination and the third, an adult and sire of the two younger dogs, had a normal haemogram and low para‐sitaemia. The morphological appearance of the erythrocyte inclusions, analysis of a 450‐bp region of the 18S rRNA gene and antibody titres provided evidence that this parasite wasBabesia gibsoni, a species not previously reported in Australia.
Number and distribution of Australian veterinarians in 1981, 1991 and 2001
Authors: HEATH TJ
Published: March 2008

Objective To analyse the number and distribution of the Australian veterinary work‐force, and to assess changes in it that have occurred since 1981.

Procedure The postcode and gender of each veterinarian who was registered, resident and apparently working in each state and territory in 1981, 1991 and 2001 was obtained from veterinary board lists, entered on an Excel data base, and analysed using the statistical program SAS System 7 for Windows 95. The Official Australian Postcode Map was used to determine the location of postcode areas, and publications of the Australian Bureau of Statistics provided data on human populations.

Results At the end of June 2001, 6358 veterinarians were registered, resident and apparently working in a state or territory of Australia. This was 100% higher than in 1981. Over the intervening 20 years, the number had increased by 3181, 2001 of whom were female. Between 1981 and 1991 the increase in major cities was 898 and in rural areas 682, of whom 357 were male. Between 1991 and 2001 the increase in cities was 1139 and rural areas 462, of whom only 98 were male. The density of veterinarians in Australia ‐ 330/million people ‐ is higher than in the UK (213/million), USA(218/million) and Canada (250/million).

Conclusions The relative number of veterinarians in Australia is now higher than in the UK, USA and Canada, and is likely to continue to increase. There is evidence of maldistribution, with many rural practices facing shortages of veterinarians with the experience and inclination to maintain veterinary services over the longer term, and some cities likely to become overcrowded with veterinarians.
Effect of periparturient diseases accompanied by excessive vulval discharge and weaning to mating interval on sow reproductive performance
Authors: WALLER CM , BILKEI G , CAMERON RDA
Published: March 2008

Objective To evaluate the effect of periparturient disease accompanied by vulval discharge, and weaning‐to‐mating intervals, on sow fertility and litter size.

Design Reproductive data were collected and analysed from 19 Hungarian swine herds over a 4 year period. Conception rates, farrowing rates and litter sizes of sows with periparturient disease accompanied by vulval discharge were used to evaluate the relationship between duration of vulval discharge and subsequent fertility and litter size. The possibility of interactions between weaning‐to‐mating intervals and duration of vulval discharges was investigated to determine if there was any effect on subsequent fertility and litter size.

Results and conclusions Both parity 1 and parity 2 to 8 sows having had periparturient disease accompanied by vulval discharge in excess of 6 days duration had significantly (P < 0.001) lower subsequent fertility (conception, farrowing and adjusted farrowing rates) compared with sows of similar parity where the duration of vulval discharge was <4 or 4 to 6 days. There was no difference in fertility rates between sows, in both parity categories, with vulval discharge for <4 days compared with 4 to 6 days. A duration of vulval discharge in excess of 6 days in parity 1 sows significantly reduced litter size (total born and live‐born) in subsequent farrowings, but not in parity 2 to 8 sows. There was no interaction between the duration of vulval discharge and post‐weaning to mating intervals. However sows with weaning to mating intervals between 7 and 10 days had smaller (P < 0.001) subsequent litter sizes compared with 3 to 6 or 11 to 14 day intervals. It was concluded that the duration of vulval discharge in excess of 6 days was an indication of a severe persistent endometritis adversely affecting fertility of sows.
Phenotypic characterisation of Australian sheep and cattle isolates of Mannheimia haemolytica, Mannheimia granulomatis and Mannheimia varigena
Authors: BLACKALL PJ , BISGAARD M , STEPHENS CP
Published: March 2008

Objective To perform a comprehensive phenotypic characterisation of 35 isolates of bacteria previously identified as haemolytic Pasteurella‐Actinobacillus and obtained from cattle and sheep.

Design The 35 isolates that had been obtained from Australian animals, 30 from cattle and five from sheep, were compared with reference strains of the five recognised species of the genus Mannheimia ‐ M haemolytica, M glucosida, M granulomatis, M ruminalisand M varigena.

Results Thirty‐four of the isolates could be confidently assigned to three species of the genus Mannheimia. Twenty‐nine were M haemolytica, with 25 being isolated from cattle and four from sheep. All but three of the bovine M haemolytica were isolated from pneumonic lungs. Of the three remaining bovine M haemolytica isolates, one was obtained in pure culture from a bovine milk sample and the other two as part of a mixed flora associated with a middle ear infection of a calf suffering mucosal disease. Of the four ovine M haemolytica isolates, two were isolated in pure culture from milk and two, also in pure culture, from pneumonic lungs. Three bovine isolates were identified as M granulomatis ‐ one from a tongue abscess, one from a jaw abscess and one from a lung showing suppurative bronchopneumonia. Two bovine isolates were identified as M varigena‐ one coming from an udder and the other from a spleen. The available diagnostic records provided no information on whether these isolates were associated with a disease process. The remaining isolate was obtained from an ovine tongue abscess and could not be assigned to a recognised species within the genus Mannheimia.

Conclusion The study represents the first time that M haemolytica, M granulomatis and M varigena have been recognised as being present in cattle and sheep in Australia. Veterinary laboratories that encounter Pasteurella‐Actinobacillus‐like organisms from cattle and sheep should attempt as complete a characterisation as possible to help improve our knowledge of the disease potential of these organsims.
Effect of the interval between shearing and dipping on the spread of Corynebacterium pseudotuberculosis infection in sheep
Authors: PATON MW , BULLER NB , ROSE IR , ELLIS TM
Published: March 2008

Objective

To determine whether the spread of Corynebacterium pseudotuberculosis infection to sheep in dips could be controlled by increasing the time between shearing and dipping.

Design

Animals and procdure

One hundred and ninety‐five sheep were found to be negative for C pseudotuberculosis exposure by assay of CLA toxin antibody, were divided into four treatment groups. Each was shorn at either 0, 2, 4 or 8 weeks before dipping in a solution containing C pseudotuber‐culosis. Blood samples were taken 6 weeks after dipping and sheep were slaughtered 12 weeks after dipping. A fifth smaller group of 14 sheep shorn 26 weeks before dipping, was also exposed to C pseudotuberculosis and was slaughtered with the other sheep.

Results

The occurrence of caseous lymphadenitis abscesses did not differ between groups or with sheep shorn 26 weeks before dipping. The proportion of sheep that sero‐converted to the C pseudotuberculosis toxin and cell wall ELISA was larger in sheep dipped immediately after shearing than in sheep in the other groups.

Conclusions

Delaying dipping until 8 weeks after shearing did not decrease the C pseudotuberculosis infection rate due to dipping. Sheep dipped immediately after shearing developed higher concentrations of antibody to C pseudotu‐berculosis than sheep when dipping occurred between 2 and 8 weeks and later after shearing.
Concurrent spirochaetal infections of the feet and colon of cattle in Japan
Authors: SHIBAHARA T. , OHYA T. , ISHII R. , OGIHARA Y. , MAEDA T. , ISHIKAWA Y. , KADOTA K.
Published: March 2008

Objective

To describe spirochaetal infections in the feet and colon of cattle affected with papillomatous digital dermatitis (PDD) and colitis respectively.

Procedure Eighty‐two slaughtered animals were macroscopically examined for the presence of PDD. Tissues of two cattle affected with PDD were examined by histology, immunohistochemistry, electron microscopy and bacteriology for spirochaetal infection.

Results

Two adult cattle (a 2‐year‐old beef bullock and 7‐year‐old Holstein dairy cow) were affected with PDD. Histologically, numerous argyrophilic and Gram‐negative filamentous or spiral spirochaetes were found deep in the PDD lesions. Epithelial and goblet cell hyperplasia and oedema of the lamina propria mucosa with macrophage and lymphocyte infiltration were observed in the caecum and colon in the cattle. Numerous spirochaetes were present in the crypts and some had invaded epithelial and goblet cells, and caused their degeneration. Immunohistochemically the organisms stained positively with polyclonal antisera against Treponema pallidum and Brachyspira (Serpulina) hyodysenteriae. Ultrastructurally, the intestinal spirochaetes were similar to the spirochaetes in PDD. They were 6 to 14 μm long, 0.2 to 0.3 μm wide and had 4 to 6 coils and 9 axial filaments per cell. Campylobacter species were isolated from the PDD and intestinal lesions, but spirochaetes were not.

Conclusion

Concurrent infections with morphologically similar spirochaetal organisms may occur in the feet and colon of cattle in Japan.
An estimate of specificity for a Johne's disease absorbed ELISA in northern Australian cattle
Authors: PITT DJ , PINCH DS , JANMAAT A. , CONDRON RJ
Published: March 2008

Objective To estimate the specificity of an absorbed enzyme‐linked immuno‐sorbent assay kitd for Johne's disease (JD) when used in mature cattle populations resident in northern Australia.

Design Blood samples were collected from beef cattle in northern Queensland, the Northern Territory and northern Western Australia, and from dairy cattle in northern Queensland. The specificity of a serological test for JD was estimated by testing the blood samples with an absorbed ELISA kit. Further samples were collected from cattle with positive ELISA results to determine the presence or absence of infection with Mycobacterium avium subsp paratuberculosis.

Procedure During 1995 and 1996, blood, tissue and gut contents were collected from beef cattle at abattoirs in Queensland and the Northern Territory; and blood and faecal samples were collected from dairy cattle in herds assessed to be most at risk for JD in northern Queensland. The blood samples were tested using an absorbed ELISA kit. Tissues and gut contents from beef cattle that had positive ELISA results were cultured for M avium subsp paratuberculosis, and tissues were examined histo‐logically. Faecal samples from dairy cattle with positive ELISA results were cultured for M avium subsp paratuberculosis.

Results Estimates of specificity for this absorbed ELISA in mature northern Australian cattle were 98.0% (97.0 to 98.8%, 95% CI) in beef cattle, and 98.3% (96.7 to 99.3%, 95% CI) in dairy cattle.

Conclusion Estimates of specificity in this study were lower for beef cattle from the Northern Territory and northern Western Australia and for dairy cattle from northern Queensland than those quoted from studies on cattle in southern Western Australia. This should be considered when serological testing using the JD ELISA is carried out on northern Australian cattle.
Derivation, safety and efficacy of a Marek's disease vaccine developed from an Australian isolate of very virulent Marek's disease virus
Authors: KARPATHY RC , FIRTH GA , TANNOCK GA
Published: March 2008

Objective To develop a serotype 1 Marek's disease (MD) vaccine from a very virulent MDV (vvMDV) pathotype and demonstrate safety and efficacy against early challenge with very virulent field strains in the presence of maternal antibody.

Study design Strain BH 16 was isolated and attenuated by serial cell culture passage. One of two cloned passages was selected for vaccine development following early laboratory‐scale protection trials in commercial birds. Comparative protection trials were carried out on the BH 16 vaccine and on a CVI 988 Rispens vaccine using commercial and SPF chickens. Challenge viruses used were either a low passage strain BH 16 virus, the Woodlands No. 1 strain or MPF 57 strain of MDV. The BH 16 vaccine was back‐passaged in SPF chickens six times and virus recovered from the final passage and the original vaccine virus were tested for safety. The immunosuppressive potential of the BH 16 and Rispens vaccines was also assessed in parallel.

Results The BH 16 and Rispens vaccines induced comparable levels of protection when used as monovalent or multi‐valent vaccines, although protection achieved with the mono‐valent vaccines was lower. No gross tumour formation was evident in any birds receiving the BH 16 vaccine or bird‐passaged virus, although microscopic lesions were present in 2/12 birds that received the bird‐passaged virus. In tests for immunosuppression, there was no histological evidence of damage to either the bursa of Fabricius or the thymus.

Conclusion The BH 16 vaccine was shown to be safe and at least as protective as the Rispens vaccine against three highly virulent MD challenge viruses.
A severe hepatic disorder with myelodysplastic syndrome, treated with cytarabine ocfosfate, in a dog
Authors: IDE K , MOMOI Y , MINEGISHI M , SEKIGUCHI M , KONNO K , IWASAKI T
Published: March 2008

An 8‐year‐old female Shih Tzu was presented with weight loss and vomiting. Alanine aminotransferase was high and abdominal radiographs revealed hepato‐ and splenomegaly. Mild anaemia, neutrophilia with left shift, eosinophilia, and thrombocytosis with dysplastic features of eosinophils and platelets, were detected. The animal was initially considered to have hepatitis and was treated accordingly, but clinical signs persisted. Histological examination of liver biopsy samples showed disruption of the hepatic lobule, with extensive infiltration by haemopoietic cells. Further investigation of the bone marrow suggested a diagnosis of myelodysplastic syndrome. The animal was treated with cytarabine ocfosfate, a prodrug of cytosine arabinoside, and appeared to recover.
Polymerase chain reaction tests for the identification of Ross River, Kunjin and Murray Valley encephalitis virus infections in horses
Authors: STUDDERT MJ , AZUOLAS JK , VASEY JR , HALL RA , FICORILLI N , HUANG J‐A
Published: March 2008

Objective To develop and validate specific, sensitive and rapid diagnostic tests using RT‐PCR for the detection of Ross River virus (RRV), Kunjin virus (KV) and Murray Valley encephalitis virus (MVEV) infections in horses.

Methods Primer sets based on nucleotide sequence encoding the envelope glycoprotein E2 of RRV and on the nonstructural protein 5 (NS5) of KV and MVEV were designed and used in single round PCRs to test for the respective viruses in infected cell cultures and, in the case of RRV, in samples of horse blood and synovial fluid.

Results The primer pairs designed for each of the three viruses amplified a product of expected size from prototype viruses that were grown in cell culture. The identity of each of the products was confirmed by nucleotide sequencing indicating that in the context used the RT‐PCRs were specific. RRV was detected in serums from 8 horses for which there were clinical signs consistent with RRV infection such that an acute‐phase serum sample was taken and submitted for RRV serology testing. The RRV RT‐PCR was analytically sensitive in that it was estimated to detect as little as 50 TCID50 of RRV per mL of serum and was specific in that the primer pairs did not amplify other products from the 8 serum samples. The RRV primers also detected virus in three independent mosquito pools known to contain RRV by virus isolation in cell culture. Samples from horses suspected to be infected with KV and MVEV were not available.

Conclusion Despite much anecdotal and serological evidence for infection of horses with RRV actual infection and associated clinical disease are infrequently confirmed. The availability of a specific and analytically sensitive RT‐PCR for the detection of RRV provides additional opportunities to confirm the presence of this virus in clinical samples. The RT‐PCR primers for the diagnosis of KV and MVEV infections were shown to be specific for cell culture grown viruses but the further validation of these tests requires the availability of appropriate clinical samples from infected horses.
Prevalence of caseous lymphadenitis and usage of caseous lymphadenitis vaccines in sheep flocks
Authors: PATON MW , WALKER SB , ROSE IR , WATT GF
Published: March 2008

Objective To estimate the prevalence of caseous lymphadenitis (CLA), determine the current usage of vaccines against CLA and to measure the effectiveness of these vaccines on sheep farms.

Design and population A survey was undertaken on 223 sheep flocks in New South Wales, Victoria and Western Australia.

Method The prevalence of CLA was measured by conventional inspection techniques at abattoirs in lines of sheep that could be traced back to a farm. Managers of the flocks were sent a questionnaire about their vaccine practices, management practices and knowledge of CLA.

Results The average prevalence of CLA in adult sheep in these flocks was 26% and varied from 20% in Western Australia to 29% in New South Wales. About 43% of sheep producers used CLA vaccines; only 12% used them as recommended. Awareness of CLA was highest in Western Australia. More producers would use CLA vaccine if they knew the prevalence of CLA in their flock and producers obtained most information about CLA from vaccine resellers.

Conclusions Only 10 to 15% of producers are currently achieving effective CLA control through the use of recommended CLA vaccination programs. In Western Australian flocks more than 25% of effectively vaccinated ewes will be sent to abattoirs in the 2 to 3 years after this study. However, large decreases in the prevalence of CLA can be achieved by about 70% of producers by either making adjustments to their vaccination programs or buying a vaccine with a CLA component. Two or three key facts on effective CLA vaccination could be made available at the point of sale of vaccines and from abattoirs that reported the prevalence of CLA to farmers.
Acute Beak and Feather Disease in juvenile African Grey parrots ‐ an uncommon presentation of a common disease
Authors: DONELEY RJT
Published: March 2008

Psittacine Beak and Feather Disease is commonly diagnosed all over the world as a viral disease of psittacine birds that primarily results in abnormalities of the feathers and beak. The clinical presentation of this disease varies between species and age groups, but in the majority of cases the course of the disease is chronic. This case report documents an acute form of the disease in African Grey parrots (Psittacus erithacus erithacus) that resulted in death without lesions in the feathers and beak.
Pathogenesis of brain damage produced in sheep by Clostridium perfringens type D epsilon toxin: a review
Authors: FINNIE JW
Published: March 2008

Microvascular endothelial damage by the epsilon toxin of Clostridium perfringens type D appears to be the fundamental cause of cerebral parenchymal injury and lesions occur in a seemingly dose‐ and time‐dependent manner. Large doses of circulating toxin produce a severe, generalised, vasogenic cerebral oedema and an acute or peracute clinical course to death. With lower doses of toxin, or in partially immune sheep, focal necrosis, often bilaterally symmetrical, occurs in certain selectively vulnerable brain regions, which appear to become fewer as the toxin dose is reduced. These cases follow a more protracted clinical course, but death is the usual outcome. The precise pathogenesis of the focal brain damage found in subacutely intoxicated sheep is unresolved, but several possible mechanisms are discussed.
A multifocal symmetrical necrotising encephalomyelopathy in Angus calves
Authors: PHILBEY AW , MARTEL KS
Published: March 2008

Objective To define a neurological disorder in Angus calves.

Procedure Clinical and pathological examinations were performed on affected Angus calves from a herd experiencing 1% annual mortality from neurological disease.

Clinical signs Angus calves developed ataxia, nystagmus, strabismus, muscular tremors, opisthotonus, bruxism, hyper‐aesthesia, tetanic spasms and episodic convulsions at 2 to 6 weeks of age. Death occurred 4 to 7 days after the onset of clinical signs.

Gross pathology Bilaterally symmetrical, yellow‐grey foci were present in the medulla oblongata.

Histopathology Symmetrical degenerative lesions affected the dorsal vagal motor, lateral cuneate and olivary nuclei in the medulla oblongata and sometimes the spinal cord, substantia nigra and cerebellar peduncles. Malacia was characterised by spongiosis of the neuropile, vascular hyper‐plasia, infiltration of gitter cells, spheroid formation and delayed degeneration of neurones.

Conclusion Angus calves may develop a multifocal symmetrical necrotising encephalomyelopathy.
Effects of the paralysis tick, Ixodes holocyclus, on the electrocardiogram of the Spectacled Flying Fox, Pteropus conspicillatus
Authors: CAMPBELL FE , ATWELL RB , SMART L
Published: March 2008

Objective To evaluate cardiac electrical function in the Spectacled Flying Fox (bat) infested with Ixodes holocyclus.

Design Prospective clinical investigation of bats treated for naturally occurring tick toxicity.

Procedure ECGs were performed on bats with tick toxicity (n =33), bats that recovered slowly (n =5) and normally (n =5) following treatment for tick toxicity, and on normal bats with no history of tick toxicity (n = 9).

Results Bats with tick toxicity had significantly prolonged corrected QT intervals, bradycardia and rhythm disturbances which included sinus bradydysrhythmia, atrial standstill, ventricular premature complexes, and idioventricular bradydysrhythmia.

Conclusions The QT prolongation observed on ECG traces of bats with tick toxi‐city reflected delayed ventricular repolarisation and predisposed to polymorphic ventricular tachycardia and sudden cardiac death in response to sympathetic stimulation. The inability to document ventricular tachycardia in bats shortly before death from tick toxicity may be explained by a lack of sympathetic responsiveness attributable to the unique parasympathetic innervation of the bat heart, or hypothermia‐induced catecholamine receptor down‐regulation. Bradycardia and rhythm disturbances may be attributable to hypothermia.
Quadrigeminal cisterna arachnoid cyst diagnosed by MRI in five dogs
Authors: KITAGAWA M , KANAYAMA K , SAKAI T
Published: March 2008

Arachnoid cysts of the quadrigeminal cisterna are infratento‐rial cystic lesions located between the collicular plate and the incisural notch of the tentorium. We report here five cases of quadrigeminal cisterna arachnoid cysts in dogs. In this study, four of the five dogs were male, three showed signs of seizures, and one dog was over 10 years of age. In two of the dogs, cysts were discovered incidentally. In previous reports, most intracranial arachnoid cysts were located in the quadrigeminal cisterna. The presence of cysts should be considered in toy breeds presenting for seizures or ataxia.
Asymptomatic anomalous pulmonary veins in a Siberian Husky
Authors: ABRAHAM LA , SLOCOMBE RF
Published: March 2008

A 2‐year‐old, neutered male Siberian Husky presented with depression, weight loss and an inability to prehend food and water. Cerebrospinal fluid was collected under general anaesthesia prior to euthanasia. The elevated white cell count comprised mostly mononuclear cells. Histological changes within the brain were variable and multifocal. Non‐suppurative meningitis secondary to lymphoma was diagnosed. At necropsy, abnormal venous drainage of the right cranial and middle lung lobes was found. A dilated major pulmonary vein from these lobes passed across the lateral aspect of the right caudal lung lobe prior to entering the heart, and subpleural veins from the affected lobes were enlarged and tortuous. These vascular abnormalities were considered incidental. There were no apparent congenital abnormalities of the heart and the animal's clinical signs were related to lymphoma of the brain.
Trilostane treatment in dogs with pituitary‐dependent hyperadreno‐corticism
Authors: BRADDOCK JA , CHURCH DB , ROBERTSON ID , WATSON ADJ
Published: March 2008

Objective

To evaluate the efficacy of trilostane in treating dogs with pituitary‐dependent hyperadrenocorticism.

Design

Prospective clinical trial using client‐owned dogs with pituitary‐dependent hyperadrenocorticism treated at University Veterinary Centre, Sydney from September 1999 to July 2001.

Procedure

Thirty dogs with pituitary‐dependent hyperadrenocorticism treated with trilostane, a competitive inhibitor β‐HSD, were monitored at days 10, 30 and 90 then 3‐monthly by clinical examination, tetracosactrin stimulation testing, urinary corticoid:creatinine ratio measurement and by client questionnaire.

Results

Twenty‐nine of 30 dogs were successfully treated with trilostane (median dose 16.7 mg/kg; range 5.3 to 50 mg/kg, administered once daily); one responded favourably but died of unrelated disease before full control was achieved.

Conclusion

Trilostane administration controlled pituitary‐dependent hyperadrenocorticism in these dogs. It was safe, effective and free of side‐effects at the doses used. Most dogs were initially quite sensitive to the drug for 10 to 30 days, then required higher doses until a prolonged phase of stable dose requirements occurred. Urinary corticoid:creatinine ratio was useful in assessing duration of drug effect. Some dogs treated for more than 2 years required reduction or temporary cessation of drug because of iatrogenic hypoadrenocorticism.
Perioperative outcomes after three different single extrahepatic portosystemic shunt attenuation techniques in dogs: partial ligation, complete ligation and ameroid constrictor placement
Authors: HURN SD , EDWARDS GA
Published: March 2008

Objective

To compare the perioperative outcomes of single extrahepatic portosystemic shunt occlusion by complete and partial silk ligation and ameroid constrictor placement in dogs.

Design

A retrospective analysis of 30 dogs with single congenital extrahepatic shunts.

Procedure

Records between 1990 and 2000 were reviewed. Patient age, breed, weight, presenting clinical signs, clinical pathology results, diagnostic imaging results, the surgery procedure performed, implant used, time taken, intra operative complications and perioperative complications were recorded. Mortality rates were calculated.

Results

Twenty dogs had a silk ligation procedure, 10 partially occluded and 10 completely. Ten dogs had an ameroid constrictor placement procedure. Ameroid constrictor surgery was significantly shorter in duration than silk ligation. Time for silk ligation was 91.8 ± 35.2 minutes (median 90.0); time for ameroid constrictor placement was 71.5 ± 12.0 (median 72.5, P = 0.049). A reduction in intraoperative complications was also noted in the ameroid constrictor surgery group.

Conclusion

The ameroid constrictor offered a surgical occlusion procedure of single extrahepatic portosystemic shunts in dogs that was clinically as effective as silk ligation in the perioperative period, with a significantly shorter surgery time.
Treatment of fractures of the mandible and maxilla by mini titanium plate fixation systems in dogs and catsa
Authors: BILGILI H. , KURUM B.
Published: March 2008

Mini titanium plates were used to repair certain fractures of the maxilla and mandible in dogs and cats, under general anaesthesia. The location of the fractures treated were: corpus mandible, one dog; corpus mandible and symphysis, two dogs; caudal mandible, two dogs; rostral mandible, one dog; maxilla, one dog; nasal bone, one dog; corpus mandible and symphysis, one cat; caudal mandible, one cat; and maxilla, one cat.

The healing periods varied from 6 to 9 weeks. In seven cases, implants were removed after a period of 3.5 to 18 months. In four cases the implants were left in place. The follow up period was between 8 and 36 months. In ten cases the procedure was successful, however in one case the outcome was not satisfactory due to a broken plate. There were no instances of dental malocclusion, nonunion, malunion, osteomyelitis or soft tissue infection. Eating, playing with toys, a fast transition to solid food and a quick return to normal jaw movements were observed.

In our hands, the mini titanium plate fixation system was a safe and effective method for repairing certain maxillary and mandibular fractures in dogs and cats.
Comparison of tracheal aspirates and bronchoalveolar lavage in racehorses 1. Evaluation of cytological stains and the percentage of mast cells and eosinophils
Authors: HUGHES KJ , MALIKIDES N. , HODGSON DR , HODGSON JL
Published: March 2008

Objective

To compare a fast Romanowsky cytological stain (Diff‐Quik®) and Leishman's stain for the detection of mast cells in samples from the lower airways of racehorses, and to compare the proportion of mast cells and eosinophils in the total inflammatory cells in tracheal aspirate (TA) with those in paired bronchoalveolar lavage (BAL) samples.

Design

Retrospective case series of 48 young Thoroughbred and Standardbred racehorses.

Procedure

Fifty‐one paired TA and BAL samples were collected after treadmill exercise from 48 horses with poor racing performance. Two slides were prepared from each sample; one was stained with Diff‐Quik® stain and the other with Leishman's stain. Differential cell counts of eosinophils and mast cells were recorded from each slide. Comparison of the suitability of the stains for the detection of mast cells, and comparisons of eosinophil and mast cell percentages in TA and BAL samples were analysed using the non‐parametric Wilcoxon matched pairs test.

Results

Percentages of mast cells were significantly higher in Leishman than in Diff‐Quik® stained slides in both TA (P = 0.03) and BAL samples (P < 0.0001). Mast cell percentages were significantly higher in BAL than in TA samples using Leishman's stain (P < 0.0001). There was no significant difference in eosinophil percentages between TA and BAL samples (P = 0.07).

Conclusions

Fast Romanowsky type stains (for example Diff‐Quik®) are not appropriate for the detection of mast cells in samples from the equine lower respiratory tract. Therefore, a metachromatic stain that reliably identifies mast cells (for example Leishman's) should be used if evaluation of mast cells in lower respiratory tract is undertaken. Mast cells are predominantly found in the distal small airways and alveoli sampled with a BAL. In contrast, eosinophils appear to be evenly distributed in the lower respiratory tract. However, high percentages of eosinophils are occasionally found only in TA samples. We recommend that both a TA and BAL be used for the evaluation of eosinophils and mast cells within the equine lower respiratory tract.
Eradication of footrot of lesser clinical severity (intermediate footrot)
Authors: ABBOTT KA , EGERTON JR
Published: March 2008

Objective

To determine if intermediate footrot (IFR) can be eradicated from a flock of sheep by inspection and culling of cases during a non‐transmission period and if prior antibiotic treatment or vaccination increases the likelihood of eradication.

Procedure

A replicated field experiment that compared the three eradication strategies was followed by an observational study of the best of these applied in a commercial flock of 3000 sheep.

Results

In the replicated experiment, IFR was eradicated either by inspection and culling alone, or when combined with vaccination. Eradication failed when the sheep were treated with parenteral antibiotics before inspection and culling during the non‐transmission period. In the whole‐flock program, eradication by repeated inspection and culling of footrot cases during the non‐transmission period was successful and the flock remained free of infection 3 years later.

Conclusions

IFR can be eradicated by inspection and culling but latent infections, which may persist undetected for at least 34 weeks, require surveillance inspections to be repeated during the non‐transmission phase of the program. The use of parenteral antibiotics as an aid to the eradication of IFR is contraindicated.
Effect of enhancing curd formation during the first colostrum feed on absorption of γ glutamy1 transferase by newborn calves
Authors: GREGORY NG
Published: March 2008

ObjectiveTo examine the effects of curd formation within the abomasum, on the absorption of g glutamyl transferase (GGT) from colostrum in newborn calves.

DesignAn in vivo physiological study with controls, and in vitro examination of calf abomasal fluid.

ProceduresNewborn calves were taken from cows without allowing them to suckle. They were fed either 1.5 kg colostrum or 1.5 kg colostrum plus rennet, with intervals between calving and colostrum feeding ranging from 0.4 to 12.7 h. Absorption of proteins from the whey component of colostrum was assessed from the rise in activity of serum GGT. In in vitro studies, colostrum was incubated with bovine amniotic fluid, newborn calf abomasal fluid or newborn calf forestomach contents, with or without rennet, to test the curd inhibiting effects of components in the abomasal fluid of newborn calves.

ResultsIn vivo: addition of rennet to the colostrum feed reduced the proportion of calves with serum GGT activity below 500 U/L by 60%. In vitro: 43% of newborn calves lacked curd forming activity in their abomasal fluid, and that deficiency was corrected by adding rennet to the incubation medium.

ConclusionsSome calves are born with low amounts of curd forming enzyme activity in the abomasum. This may compromise their ability to absorb large whey proteins from the first feed of colostrum. Adding rennet to the first colostrum feed may improve passive immunity in those calves.
Letters
Authors: Auld Dr Michael , Brain Dr Philip H
Published: March 2008

Editor's note: The AVJ welcomes letters from members in all areas of the profession on matters of importance to you. Please keep them brief ‐ to meet our space constraints. Letters will be subject to minimal editing procedures. Subject to letters complying with the AVJ's legal responsibilities, they will not be censored. Nor will individuals or groups waging ‘campaigns’ be permitted to abuse these pages. If submitting a letter intended for publication, kindly identify it as such. Letters to the Editor can be sent by mail, fax or e‐mail at the contact points listed at the start of the News Section. Writers may use a pseudonym to protect their identities ‐ but must supply the Editor with verifiable names and points of contact.
The effect of shade, shearing and wool type in the protection of Merino sheep from Hypericum perforatum (St John's wort) poisoning
Authors: BOURKE CA
Published: March 2008

Objective To investigate the roles of shade, fleece length and wool type in the protection of sheep from Hypericum perforatum poisoning.

Animals Adult Merino ewes of superfine, fine and medium wool type.

Design Seventy sheep were divided into seven equal groups. During late spring and summer a series of successive, replicate experiments was conducted, each using one group and lasting 5 days. The sheep carried 14 to 24 weeks wool growth. In each experiment the treatments tested were Hypericum+, sunlight + (n= 7); Hypericum+, sun ‐ (n = 1); Hypericum ‐, sun + (n = 1); Hypericum ‐, sun ‐ (n = 1).

Next,24 sheep in two equal groups were used in experiments of similar design to the above. Each group consisted of nine recently (1 to 3 weeks previously) shorn and three wool covered (25 to 26 weeks growth) sheep. The treatments tested were Hypericum+, sunlight+, fleece ‐ (n= 9); Hypericum+, sun ‐, fleece + (n= 1); Hypericum ‐, sun +, fleece + (n= 1); Hypericum ‐, sun ‐, fleece + (n= 1).

Procedures Finely milled Hypericum was administered by gavage to provide 3 mg hypericin / kg body weight. Sheep were sheltered from direct sunlight or were exposed for 5 h per day for 4 successive post‐treatment days. Rectal temperatures were measured immediately before and at the end of each sunlight exposure session. Rectal temperature above 40°C was considered indicative of hypericin poisoning.

Results After Hypericum treatment hypericin poisoning was displayed by 26.5% of woolled sheep that were exposed to sunlight, but by none of those that were fully shaded. In similarly treated but recently shorn sheep 94% displayed hypericin poisoning when exposed to sunlight. In the wool covered group the percentages of poisoned animals based on wool type were: superfine 14%, fine 28.5%, medium 33.3%. In the recently shorn group the percentage for all three approached 100%.

Conclusions A majority of Merinos with at least 14 weeks wool growth will not be poisoned by a single oral dose of 3 mg hypericin /kg, but because hypericin persists in the blood circulation for several days this safe dose will be lowered by continuous daily ingestion. Sheep with access to substantial areas of shade could safely ingest much greater amounts of hypericin. Wool removal greatly increases the risk of poisoning. Superfine Merinos with a wool cover should be able to ingest more hypericin than comparable, medium wool types, without any increased risk of poisoning. The ability of ruminant livestock to safely ingest Hypericum is probably determined more by the amount of skin protection they have against incident sunlight than by differences in hypericin metabolism and excretion capacity.
Cryptosporidium muris infection in bilbies (Macrotis lagotis)
Authors: WARREN KS , SWAN RA , MORGAN‐RYAN UM , FRIEND JA , ELLIOT A
Published: March 2008

Cryptosporidiosis is an enteric disease of animals and humans that can be fatal in immunocompromised individuals. There is no known effective treatment for cryptosporidiosis. Bilbies are threatened marsupials and are bred in captivity as part of a recovery program to re‐introduce this species to the southwest of Western Australia. Cryptosporidium muris infection was detected in the faeces of bilbies at a captive breeding colony. Stress associated with a high density of bilbies in enclosures may have predisposed some of the bilbies to infection with C muris. C muris has been described in mice and was found in the faeces of one mouse trapped in the breeding enclosures. It is likely the bilbies acquired the infection from mice by faecal contamination of food and water. The infection cleared within 2 months from some bilbies, however others remained infected for 6 months and treatment was attempted with dimetridazole. Subsequently the parasite was no longer be detectable in the faeces.