Porcine circovirus-associated disease in weaner pigs in Western Australia.

OBJECTIVE: To report the occurrence and pathology of porcine circovirus type 2 (PCV2)-associated disease (PCVAD) of postweaning pigs in two Australian pig herds. METHODS: Mortality data from two commercial piggeries that experienced higher than normal postweaning illthrift and mortalities were examined. Gross and histopathological examinations were performed on the index cases, and at weekly intervals thereafter for a period of 10 weeks. Specimens were submitted to the laboratory for routine diagnostic testing and for exclusion of porcine reproductive and respiratory syndrome virus (PRRSV). The genomes of two strains of PCV2 isolated during testing were sequenced. RESULTS: Mortality rates in weaned, 5-12-week-old pigs spiked significantly during mid to late 2007. This increase in the mortalities was mainly attributed to salmonella-associated diarrhoea and illthrift. Salmonellosis was diagnosed in 73/110 cases inclusive of both piggeries. Many pigs also had chronic granulomatous lymphadenitis and diffuse histiocytic interstitial pneumonia consistent with PCVAD and associated with varying amounts of PCV2 antigen and inclusion bodies. All samples tested for PRRSV were negative. Sequence analysis of the PCV2 isolates showed strain differences between piggeries. CONCLUSION: This report describes the first outbreaks of PCVAD in growing pigs in Western Australia (WA) and describes lesions not previously seen in this laboratory. It also describes the first isolation of a PCV2 group 1 virus in WA associated with PCVAD. Although the outbreaks of PCVAD occurred with concurrent salmonellosis, the two diseases were unrelated. Neither of the outbreaks met the Australian case definition for the diagnosis of postweaning multisystemic wasting syndrome.

Vaccine efficacy for reducing turbinate atrophy and improving growth rate in piggeries with endemic atrophic rhinitis.

Two vaccines, based on formalin-killed whole cells of toxigenic Pasteurella multocida type D and Bordetella bronchiseptica combined with a partially toxoided cell extract of P multocida, were prepared with Freund's incomplete adjuvant (vaccine 1) or by alum precipitation (vaccine 2). Each was tested for safety and efficacy in reducing the severity of nasal turbinate atrophy and improving the growth rate of pigs in three Western Australian commercial piggeries with endemic atrophic rhinitis. In safety experiments with vaccine 1, no adverse clinical effects were observed in vaccinated sows or their progeny. Piglets receiving vaccine 2 showed no injection site abnormalities, pyrexia or turbinate atrophy. In field trials, vaccine 1 significantly reduced the prevalence of moderate to severe nasal turbinate atrophy (Done score 3 to 5) when used in two piggeries (A and B). Progeny from vaccinated sows in piggery B also grew significantly faster than controls. When vaccine 2 was used in piggery A at a later date and in another piggery (C), growth rate was not improved in either piggery and the prevalence of moderate to severe turbinate atrophy was reduced only in piggery C.

A cross-sectional study to show Eperythrozoon ovis infection is prevalent in Western Australian sheep farms.

A serological survey and risk factor study was conducted to estimate the prevalence of Eperythrozoon ovis infection in Western Australian weaner sheep, the prevalence of farms with infected sheep, and to identify factors affecting initiation and maintenance of infection on the farm. The study was conducted on 91 farms, purposively chosen from 41 randomly selected regional shires stratified by sheep number and rainfall zones. Twenty sheep were selected systematically from a mixed-sex flock on each farm and tested for serum antibody to E ovis using an enzyme-linked immunosorbent assay. Information on putative risk factors was collected using an interview questionnaire. Antibody to E ovis was detected in 4.5% of sheep on 47% of the farms sampled. The prevalence of E ovis infection in sheep was estimated at the 95% confidence level to be between 3.6 and 5.5%, and the prevalence of farms with infected sheep was estimated to be between 37.5 and 56.5%. Most farms with serological evidence of infection occurred in the Great Southern agricultural region (79.5%), south-east of Perth through to Albany (latitude 32 to 34 degrees S, longitude 116 to 120 degrees E), and in the Northern region (12.8%) surrounding Geraldton (latitude 29 degrees S, longitude 114 degrees E). There were significantly more farms (P less than 0.05) with evidence of infection in the Great Southern region compared to the Central region between Geraldton and Perth, and on farms in the region south compared to north of latitude 32 degrees S. None of the putative risk factors examined in the questionnaire were associated with serological evidence of infection on the farm.(ABSTRACT TRUNCATED AT 250 WORDS)

Disseminated aspergillosis in dogs.

Clinical and pathological findings are reported from a series of 12 cases of disseminated aspergillosis (A. terreus) in 11 German Shepherd dogs and one Dalmatian referred to Murdoch University Veterinary Hospital (MUVH) over the period 1980 to 1984. A preliminary study of humoral and cell mediated immune components and complement levels revealed no consistent abnormality in 9 dogs tested apart from raised IgG levels. Serum IgA levels were depressed in 30% of cases. Serial data from one extensively monitored case is presented. The unusual epidemiological and pathogenetic features of the disease are discussed.

The pathology of disseminated Aspergillus terreus infection in dogs.

Disseminated Aspergillus terreus infection was diagnosed in ten previously healthy adult dogs--nine German shepherds and one dalmatian. The disease was characterized by the presence of multiple granulomas and infarcts in a wide range of organs. The kidney, spleen, and skeletal system were most commonly and severely affected. Fungal hyphae were demonstrated in large numbers within granulomas and thrombi, and A. terreus was readily isolated by culture. This disseminated mycosis appears unique; in this series of cases there was no apparent predisposing factor, portal of entry, or primary focus for dissemination of the infection.

Local current field radio frequency hyperthermia for the treatment of superficial skin tumours in cats.

Local current field radiofrequency (LCF-RF) hyperthermia was used to treat 38 superficial skin tumours (predominantly squamous cell carcinomas) of the nose, face and ears in 35 cats. LCF-RF hyperthermia was applied at 50 degrees C for 60 seconds at single or multiple sites depending on the tumour size. Each cat was observed over a four-month period after treatment and 14 out of 35 cases were also available for re-evaluation eight months after treatment. Tumours which had not resolved completely within one month after the initial treatment were re-treated. LCF-RF hyperthermia is most suited for the treatment of superficial skin tumours (<5 mm diameter). Ninety-two per cent (12/13) of tumours of this dimension showed some regression and 69% (9/13) completely resolved. Larger tumours >5mm diameter) were also successfully treated. 54% (8/14) regressed but only 14% (2/14) completely resolved. LCF-RF hyperthermia is not recommended for the treatment of tumours of the pinnae as 5 of the 6 tumours at this site failed to respond.