Use of intralesional oestradiol concentration to identify a functional pulmonary metastasis of canine sertoli cell tumour.

A seven-year-old, 31 kg male neutered Labrador was investigated for signs of feminisation syndrome and prostatic disease four years after castration and removal of a testicular sertoli cell tumour (SCT). Investigations revealed an elevated serum oestradiol-17beta concentration, a pulmonary mass containing fluid high in oestradiol-17beta and cystic changes in the prostate gland. The pulmonary mass was surgically excised and histologically confirmed to be a SCT metastasis. To the authors' knowledge, this is the first reported case of a proven functional extranodal SCT metastasis and the first to be diagnosed by oestradiol-17beta measurement of intralesional fluid.

Clinicopathological presentation of cardiac disease in cattle and its impact on decision making.

The records of 116 cattle suffering from cardiac disease were examined retrospectively. On the basis of the results of postmortem examinations there were 52 cases of endocarditis, 39 of pericarditis and 25 congenital cardiac defects. The most useful clinical tool for differentiating between these conditions was auscultation of the heart. The cases of pericarditis were characterised by muffled heart sounds, and the cases of endocarditis and congenital cardiac defects were characterised by a cardiac murmur. Endocarditis could be differentiated from congenital cardiac defects by the presence of a jugular pulse, venous distension, oedema, a reduced appetite, pain and polyarthritis, whereas congenital defects were associated with conformational abnormalities. These two conditions could also be differentiated by differences in the plasma sodium concentration, the albumin:globulin ratio, red blood cell count, lymphocyte count and haematocrit. The ability to differentiate between these three groups of cardiac diseases can help the veterinary practitioner in deciding whether treatment, economic salvage (slaughter for human consumption) or disposal (slaughter not for human consumption) is likely to be the best option.

Infection with Menangle virus in flying foxes (Pteropus spp.) in Australia.

OBJECTIVE: To examine flying foxes (Pteropus spp.) for evidence of infection with Menangle virus. DESIGN: Clustered non-random sampling for serology, virus isolation and electron microscopy (EM). PROCEDURE: Serum samples were collected from 306 Pteropus spp. in northern and eastern Australia and tested for antibodies against Menangle virus (MenV) using a virus neutralisation test (VNT). Virus isolation was attempted from tissues and faeces collected from 215 Pteropus spp. in New South Wales. Faecal samples from 68 individual Pteropus spp. and four pools of faeces were examined by transmission EM following routine negative staining and immunogold labelling. RESULTS: Neutralising antibodies (VNT titres > or = 8) against MenV were detected in 46% of black flying foxes (P. alecto), 41% of grey-headed flying foxes (P. poliocephalus), 25% of spectacled flying foxes (P. conspicillatus) and 1% of little red flying foxes (P. scapulatus) in Australia. Positive sera included samples collected from P. poliocephalus in a colony adjacent to a piggery that had experienced reproductive disease caused by MenV. Virus-like particles were observed by EM in faeces from Pteropus spp. and reactivity was detected in pooled faeces and urine by immunogold EM using sera from sows that had been exposed to MenV. Attempts to isolate the virus from the faeces and tissues from Pteropus spp. were unsuccessful. CONCLUSION: Serological evidence of infection with MenV was detected in Pteropus spp. in Australia. Although virus-like particles were detected in faeces, no viruses were isolated from faeces, urine or tissues of Pteropus spp.

Pathological fractures secondary to metaphyseal osteopathy in a dog.

A four-month-old German Shepherd Dog (GSD) was admitted with bilateral non-weight bearing hindlimb lameness and pyrexia. A diagnosis of bilateral distal femoral fractures secondary to metaphyseal osteopathy was made on the basis of clinical signs, radiography and biopsy. The dog returned to normal function following conservative management. As far as the authors are aware there are no previous reports of pathological fractures secondary to this condition.

Skeletal and neurological malformations in pigs congenitally infected with Menangle virus.

OBJECTIVE: To describe the pathological findings in stillborn piglets and fetuses delivered by sows naturally infected with Menangle virus, a recently recognised Paramyxovirus. DESIGN: Observations of the gross and microscopic pathology of natural disease. PROCEDURE: Postmortem examinations were performed on 49 stillborn piglets, 35 mummified or semi-mummified full-term fetuses and 6 aborted fetuses from 20 litters at a 2600-sow intensive piggery in New South Wales during an outbreak of reproductive disease from June to September 1997. Body weights, crown-rump lengths and gross pathological changes were recorded. Tissues, including brain and spinal cord, were processed for histopathological examination. RESULTS: Litters with reduced numbers of live born piglets had mummified fetuses and stillborn piglets. Affected stillborn and aborted piglets frequently had arthrogryposis, craniofacial and spinal deformities, pulmonary hypoplasia and degeneration of the brain and spinal cord. Intranuclear and intracytoplasmic inclusion bodies were observed in neurones and other cells in the brain and spinal cord in association with extensive degeneration, necrosis, infiltration of macrophages and gliosis. CONCLUSIONS: In utero infection of piglets with Menangle virus is associated with severe skeletal and neurological malformations.

Evidence for the expression and enzymatic activity of haem oxygenase-1 in the lungs of horses.

The aim of this study was to characterise the expression of haem oxygenase-1 (HO-1) in healthy lung tissue from horses and to measure its activity. Samples of lung tissue were collected from six horses euthanased for reasons other than respiratory disease. HO-1 expression and activity were detected in type II alveolar epithelial cells, macrophages and neutrophils in all the samples examined. The activity was dependent on the presence of NADPH and inhibited quantitatively by the addition of increasing concentrations of a competitive inhibitor of HO-1, tin mesoporphyrin IX.

Ureteral fibroepithelial polyp in a dog.

Haematuria in a dog occurred secondarily to a unilateral ureteral fibroepithelial polyp. The diagnostic techniques, gross pathology and histopathological findings of this unusual benign tumour are reported. Complete resolution of clinical signs occurred following ureteronephrectomy.

Dynamic tracheal collapse associated with disseminated histiocytic sarcoma in a cat.

This case report describes an unusual presentation of histiocytic sarcoma in a domestic shorthair cat. Initial investigation revealed a haemodynamically insignificant hypertrophic cardiomyopathy, bronchitis and a mild irregularity of the cervical trachea. The cat's disease progressed over a two-week period. Repeat radiography and tracheoscopy revealed a marked dynamic tracheal collapse associated with a raised plaque-like lesion within the cervical trachea. Subsequent post-mortem examination and histopathology revealed disseminated histiocytic sarcoma involving the trachea and kidneys. This is the first reported case of a histiocytic sarcoma involving the trachea in either dogs or cats.

Infectious canine hepatitis in red foxes (Vulpes vulpes) in wildlife rescue centres in the UK.

Outbreaks of infectious canine hepatitis are described in red foxes ( ITALIC! Vulpes vulpes) at two wildlife rescue centres in the UK. Disease occurred in two-month-old to four-month-old juvenile foxes, which were held in small enclosures in groups of three to eight animals. The foxes died or were euthanased after a short clinical course, sometimes including neurological signs and jaundice, with a high case fatality rate. Four red foxes submitted for postmortem examination had enlarged, congested livers, with rounded borders and mild accentuation of the lobular pattern. On histological examination, there was random, multifocal to massive hepatic necrosis, along with multifocal vasculitis in the central nervous system (CNS) and mild, multifocal glomerulonephritis. Intranuclear inclusion bodies, typical of canine adenovirus type 1 (CAV-1) infection, were present in hepatocytes, vascular endothelial cells in the CNS, renal glomeruli and renal tubular epithelial cells. CAV-1 was detected in tissues from affected foxes by PCR and sequencing. Congregation of juvenile foxes in wildlife rescue centres is likely to be a risk factor for transmission of CAV-1. Preventive measures in wildlife centres should be implemented to prevent the spread of the virus among conspecifics and to other susceptible species.

Assessment of antibodies to rabbit haemorrhagic disease virus in fox serum as an indicator of infection in sympatric rabbit populations.

OBJECTIVE: To assess the value of foxes as indicators of rabbit haemorrhagic disease virus in sympatric populations of rabbits. DESIGN: Serum samples from 341 foxes in central western New South Wales were tested for exposure to rabbit haemorrhagic disease virus using antibody cELISAs. Selected samples were tested for viral antigens by ELISA, viral nucleic acids by reverse transcriptase PCR and viral infectivity by rabbit inoculation. RESULTS: Antibodies against rabbit haemorrhagic disease virus were first detected in foxes 4 months after rabbit haemorrhagic disease was observed in rabbits in the same area. There was evidence of exposure of foxes to the virus in two subsequent years. A proportion of antibody positive, inconclusive and negative serum samples from foxes gave false positive results in an antigen ELISA for rabbit haemorrhagic disease virus. These serum samples were negative for viral nucleic acid by reverse transcriptase PCR and for infectious virus by rabbit inoculation. Liver samples from foxes were negative for viral antigens. CONCLUSIONS: Antibodies against rabbit haemorrhagic disease virus in fox serum can serve as an index of the occurrence of rabbit haemorrhagic disease in rabbit populations. Some fox serum samples exhibit false positive reactivity in an antigen ELISA for rabbit viral haemorrhagic disease virus.

A multifocal symmetrical necrotising encephalomyelopathy in Angus calves.

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, hyperaesthesia, 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 hyperplasia, infiltration of gitter cells, spheroid formation and delayed degeneration of neurones. CONCLUSION: Angus calves may develop a multifocal symmetrical necrotising encephalomyelopathy.

A neurological locomotor disorder in sheep grazing Stachys arvensis.

OBJECTIVE: To describe the clinical signs and pathology of a neurological locomotor disorder in sheep associated with ingestion of Stachys arvensis. DESIGN: Field observations and laboratory examinations. PROCEDURE: Clinical and pathological examinations were performed on sheep with suspected S arvensis intoxication. FIELD OBSERVATIONS: Merino sheep in a flock on the southwestern slopes of New South Wales developed a neurological disorder after grazing S arvensis. Affected animals had pelvic limb paresis and a proprioceptive deficit. When forced to exercise they stumbled and collapsed. Recovery following removal from the plant was slow. Many deaths were associated with the outbreak. RESULTS: Affected sheep developed a mild degenerative myelopathy and peripheral neuropathy. Deficiencies of vitamins A and E were also observed in the affected flock. CONCLUSION: Grazing S arvensis is sometimes associated with a neurological locomotor disorder in sheep.

Meningoencephalitis and other conditions associated with Histophilus ovis infection in sheep.

Histophilus ovis was isolated from 29 sheep in 20 flocks and 2 artificial insemination (AI) centres in southern New South Wales from 1984 to 1990. The clinical and pathological findings were consistent with previous reports and included polyarthritis (7 flocks), epididymo-orchitis (5), meningoencephalitis (3), pneumonia (3), septicaemia (2), mastitis (1) and metritis (1). Six sheep had meningoencephalitis, a syndrome not previously associated with H ovis infection in sheep, which was similar pathologically to thromboembolic meningoencephalitis in cattle, caused by the related organism, Haemophilus somnus. H ovis was isolated from the semen of 12-month-old rams in a flock that had polyarthritis due to H ovis, in 4-month-old ram lambs and from the uterus of a ewe in a flock that had sporadic cases of H ovis septicaemia.

Spironucleosis in Australian king parrots (Alisterus scapularis).

OBJECTIVE: To describe a syndrome of wasting, diarrhoea and mortality in Australian king parrots (Alisterus scapularis). DESIGN: Field observations and laboratory examinations. Procedure Pathological examinations were performed on 50 Australian king parrots with wasting and diarrhoea. Wet preparations of intestinal contents were examined by light microscopy. Tannins were extracted from acorns (Quercus sp) and tested for toxicity in mice. CLINICAL SIGNS AND EPIDEMIOLOGY: A syndrome of wasting, diarrhoea and mortality was observed in wild juvenile Australian king parrots in eastern Australia from 1984 to 2000. Sporadic cases and outbreaks of disease occurred from May to September in New South Wales, the Australian Capital Territory and Victoria. Outbreaks in the Australian Capital Territory in 1990 and 1991 were associated with parrots congregating to feed on acorns. Most affected birds failed to respond to treatment with dimetridazole and died 1 to 14 days after hospitalisation. Selected cases recovered following treatment with metronidazole. PATHOLOGY: Affected birds were emaciated, with faecal matting of feathers around the cloaca and yellow-green fluid, foamy intestinal contents. Abundant motile Spironucleus trophozoites were observed in wet preparations of faeces of clinically affected birds and intestinal contents of birds examined within 1 h of death. Protozoa were detected histologically in crypts of Lieberkühn in the intestine in association with exudation of mucus (catarrhal enteritis) or lymphoplasmacytic enteritis. Toxicology Tannin extracts from acorns induced periacinar hepatic necrosis in mice. CONCLUSION: Wasting, diarrhoea and mortality in wild juvenile Australian king parrots were associated with Spironucleus-like protozoa in the intestine. Acorns were not considered to be the cause of the syndrome.

Yersinia species isolated from sheep with enterocolitis.

In 40 submissions to the Regional Veterinary Laboratory (RVL) Wagga Wagga from sheep in southern New South Wales from 1981 to 1989, 53 isolates of Yersinia sp were recovered from 45 sheep in 37 flocks. Of 53 isolates, 26 were identified as Y. pseudotuberculosis, 20 as Y. enterocolitica, 5 as Y. intermedia and 2 as Y. frederiksenii. Twelve isolates of Y. pseudotuberculosis tested in the slide agglutination test all belonged to serotype III. The 20 Y. enterocolitica isolates were categorised biochemically as biotype 5 strains and, of 6 isolates serotyped, all belonged to serogroup 2,3. Outbreaks of yersiniosis were most common in late winter and early spring and affected flocks often had experienced a change in husbandry. Infection with Yersinia sp was associated with diarrhoea, illthrift and mortality. At necropsy, congestion and occasionally thickening of the intestinal mucosa were observed in affected sheep. Gastrointestinal nematodiasis and coccidiosis often were concurrent findings. The characteristic histological lesion in sheep infected with Y. pseudotuberculosis was acute segmental suppurative erosive enterocolitis. There were no lesions consistently associated with Y. enterocolitica, Y. intermedia or Y. frederiksenii.

Anasarca and myopathy in ostrich chicks.

Twenty ostrich chicks that died at, or within, 1 week after hatching were examined from 7 farms with poor (43 to 75%) hatchability. All chicks had anasarca and 15 had mild, generalised, acute degenerative changes in the complexus and pelvic limb muscles. One had fibrinoid degeneration of arterioles. Biochemical examinations produced no evidence of deficiencies of selenium, vitamin A or vitamin E. The syndrome was related to high relative humidity during incubation. Malpositioning also was a cause of embryo mortality.

Epidemiology and control of Menangle virus in pigs.

OBJECTIVE: To describe the epidemiology and eradication of Menangle virus infection in pigs. DESIGN: Field observations and interventions, structured and unstructured serological surveys, prospective and cross-sectional serological studies and laboratory investigations. PROCEDURE: Serum samples were collected from pigs at a 2600-sow intensive piggery in New South Wales that experienced an outbreak of reproductive disease in 1997. Serum samples were also collected from piggeries that received pigs from or supplied pigs to the affected piggery and from other piggeries in Australia. Serum and tissue samples were collected from pigs at piggeries experiencing reproductive disease in New South Wales. Sera and faeces were collected from grey-headed flying foxes (Pteropus poliocephalus) in the region of the affected piggery. Serum samples were tested for neutralising antibodies against Menangle virus. Virus isolation was attempted from faeces. RESULTS: Following the outbreak of reproductive disease, sera from 96% of adult pigs at the affected piggery, including sows that produced affected litters, contained neutralising antibodies against Menangle virus. Neutralising antibodies were also detected in sera from 88% of finisher pigs at two piggeries receiving weaned pigs from the affected piggery. No evidence of Menangle virus infection was found in other piggeries in Australia. In cross-sectional studies at the affected piggery, colostral antibodies were undetectable in most pigs by 14 to 15 weeks of age. By slaughter age or entry to the breeding herd, 95% of pigs developed high antibody titres (> or = 128) against Menangle virus in the virus neutralisation test. Menangle virus was eradicated from the affected piggery following a program of serological testing and segregation. Neutralising antibodies against Menangle virus were also detected in P poliocephalus from two colonies in the vicinity of the affected piggery. Two piggery workers were infected with Menangle virus. There was no evidence of infection in cattle, sheep, birds, rodents, feral cats and a dog at the affected piggery. CONCLUSIONS: Serological evidence of infection with Menangle virus was detected in pigs at a piggery that had experienced reproductive disease, in pigs at two associated piggeries and in fruit bats in the region of the piggery. Two humans were infected. The mode of transmission between pigs is unknown, but spread by faecal or urinary excretion is postulated. This virus can be eradicated by the segregation of pigs into discrete age groups.

Reproductive disease and congenital malformations caused by Menangle virus in pigs.

OBJECTIVE: To describe a new syndrome characterised by embryonic mortalities, stillbirths, mummified foetuses and congenital malformations in a herd of intensively farmed pigs. DESIGN: Field observations, laboratory investigations and examination of breeding records. PROCEDURE: Pathology examinations were performed on mummified and congenitally deformed piglets during an outbreak of reproductive disease at a 2600 sow intensive piggery in New South Wales from April to October 1997. Reproductive performance was monitored during the outbreak and breeding records were examined retrospectively. Serum and tissue samples from pigs were tested for evidence of infection with known porcine pathogens and for a new virus, Menangle virus, isolated from stillborn piglets with deformities from the affected piggery in August 1997. RESULTS: Reproductive disease occurred sequentially in all four breeding units at the affected piggery over a period of 21 weeks. The farrowing percentages in each unit decreased from 80 to 82% before the outbreak to 63 to 78% during the outbreak and the number of live piglets per litter declined from a mean of 9.6 to 9.8 before the outbreak to 7.2 to 8.9 during the outbreak. The proportion of affected litters (litters with less than six liveborn piglets) was highest (64%) in the sixth week of the outbreak. Mummified foetuses, stillborn piglets with arthrogryposis, craniofacial deformities and degeneration of the brain and spinal cord, were observed along with occasional abortions. Sera from sows that produced affected litters contained neutralising antibodies against Menangle virus and there was evidence that this virus had been introduced to the piggery in February 1997. CONCLUSIONS: Reproductive disease in pigs due to Menangle virus was characterised by stillbirths, mummification, embryonic death and infertility, along with abortions, skeletal deformities and degeneration of the brain and spinal cord in affected foetuses and stillborn piglets.