Hepatotoxicosis in dogs consuming a diet of camel meat contaminated with indospicine.

BACKGROUND: Four dogs presented with clinical signs of severe hepatic disease after consuming a commercial camel meat diet. METHODS: Laboratory investigation revealed evidence of severe liver disease, including markedly increased serum alanine aminotransferase (ALT) activity and total bilirubin concentration, and prolonged clotting times. RESULTS: Two dogs deteriorated despite supportive therapy and were euthanased. Histologically, both livers appeared similar, with the main lesion being extensive periacinar necrosis and haemorrhage. Indospicine, a toxic amino acid of plant origin, was detected in the serum and/or plasma from all four dogs, as well as in tissues of a dog that was necropsied and in a sample of the camel meat fed to this animal. Serum biochemistry tests using blood samples collected from 15 additional dogs identified as having eaten the diet detected indospicine was in the serum of 14 and 3 had increased ALT activity. One of the latter dogs subsequently developed clinical signs of severe liver disease and was euthanased. CONCLUSION: To the authors' knowledge, this is the first published report of the detection of indospicine residues in camel meat and the occurrence of severe, sometimes fatal, liver disease in dogs that consumed this contaminated meat.

Remission of histiocytic ulcerative colitis in Boxer dogs correlates with eradication of invasive intramucosal Escherichia coli.

BACKGROUND: Historically, histiocytic ulcerative (HUC) (or granulomatous) colitis of Boxer dogs was considered an idiopathic immune-mediated disease with a poor prognosis. Recent reports of dramatic responses to enrofloxacin and the discovery of invasive Escherichia coli within the colonic mucosa of affected Boxer dogs support an infectious etiology. HYPOTHESIS: Invasive E. coli is associated with colonic inflammation in Boxer dogs with HUC, and eradication of intramucosal E. coli correlates with clinical and histologic remission. ANIMALS: Seven Boxer dogs with HUC. METHODS: Prospective case series. Colonic biopsies were obtained at initial evaluation in 7 dogs, and in 5 dogs after treatment with enrofloxacin. Biopsies were evaluated by standardized histopathology, and fluorescence in situ hybridization (FISH) with probes to eubacteria and E. coli. RESULTS: Intramucosal E. coli was present in colonic biopsies of 7/7 Boxers with HUC. Clinical response was noted in all dogs within 2 weeks of enrofloxacin (7 + or - 3.06 mg/kg q24 h, for 9.5 + or - 3.98 weeks) and was sustained in 6 dogs (median disease-free interval to date of 47 months, range 17-62). FISH was negative for E. coli in 4/5 dogs after enrofloxacin. E. coli resistant to enrofloxacin were present in the FISH-positive dog that relapsed. CONCLUSIONS AND CLINICAL RELEVANCE: The correlation between clinical remission and the eradication of mucosally invasive E. coli during treatment with enrofloxacin supports the causal involvement of E. coli in the development of HUC in susceptible Boxer dogs. A poor response to enrofloxacin treatment might be due to colonization with enrofloxacin-resistant E. coli.

Intracellular ciliated protozoal infection in silverlip pearl oysters, Pinctada maxima (Jameson, 1901).

The pathology associated with an intracellular ciliate infection in the digestive gland of pearl oysters Pinctada maxima (Jameson, 1901) is described. Histopathological and transmission electron microscopic examination were used to characterise the organism and its location within host cells. The parasite is tear-drop shaped measuring 5.53 microm (range of 2.73-7.47 microm, n=9) in width and 11.15 microm (range of 9.02-16.2 microm) in length with a centrally located lobulated nucleus and a large nucleus:cytoplasmic ratio. The ciliate has nine evenly spaced rows of cilia running obliquely along the length of cell, converging on the pointed end. Infected digestive glands typically had a moderate to severe infiltration with mononuclear hemocyte. A strong correlation existed between the burden of ciliates and the host response; (p<0.001, C=0.315 Pearson Correlation). The use of a single tissue section upon microscopic examination was found to detect only 38-50% of the infections. However, examination of serial haematoxylin and eosin stained sections improved the reliability of detecting infection.

Hypokalaemic paresis, hypertension, alkalosis and adrenal-dependent hyperadrenocorticism in a dog.

Generalised paresis, severe hypokalaemia and kaliuresis, metabolic alkalosis and hypertension, characteristic of mineralocorticoid excess, were identified in a dog with hyperadrenocorticism due to a functional adrenocortical carcinoma. Aldosterone concentration was decreased and deoxycorticosterone concentration increased in the presence of hypokalaemia. These metabolic abnormalities resolved with resection of the carcinoma. Mineralocorticoid excess in dogs with hyperadrenocorticism is generally considered to be of little clinical significance but resulted in the acute presentation of this patient. The possible pathogenesis of mineralocorticoid excess in this case of canine hyperadrenocorticism is discussed.

Cutaneous papillomatosis and carcinomatosis in the Western barred bandicoot (Perameles bougainville).

A progressive wart-like syndrome in both captive and wild populations of the Western barred bandicoot (WBB) is hindering conservation efforts to prevent the extinction of this endangered marsupial. In this study, 42 WBBs exhibiting the papillomatosis and carcinomatosis syndrome were examined. The disease was characterized by multicentric proliferative lesions involving cutaneous and mucosal surfaces, which were seen clinically to increase in size with time. Grossly and histologically the smaller skin lesions resembled papillomas, whereas the larger lesions were most commonly observed to be squamous cell carcinomas. Large amphophilic intranuclear inclusion bodies were observed in hyperplastic conjunctival lesions of 8 WBBs under light microscopy. Conjunctival lesions from 2 WBBs examined using transmission electron microscopy contained a crystalline array of spherical electron-dense particles of 45-nm diameter, within the nucleus of conjunctival epithelial cells, consistent with a papillomavirus or polyomavirus. Conjunctival samples from 3 bandicoots that contained intranuclear inclusion bodies also demonstrated a positive immunohistochemical reaction after indirect immunohistochemistry for papillomavirus structural antigens. Ultrastructural and/or immunohistochemical evidence of an etiologic agent was not identified in the nonconjunctival lesions examined. Here we describe the gross, histopathologic, ultrastructural, and immunohistochemical findings of a papillomatosis and carcinomatosis syndrome recently identified in the WBB.

Klossiella quimrensis (Apicomplexa: Klossiellidae) causes renal coccidiosis in western barred bandicoots Perameles bougainville (Marsupialia: Peramelidae) in Western Australia.

Previous studies have described a range of Klossiella species parasitic in marsupial hosts. Klossiella quimrensis is the etiologic agent of renal coccidiosis in the peramelid marsupial hosts Isoodon obesulus and Perameles gunnii in Eastern Australia, but there is no previous report of klossiellosis in Western Australian peramelids. This study describes klossiellosis diagnosed by histology of renal tissue sections collected during necropsy of 20 Perameles bougainville between 2000 and 2005. Sporonts, sporoblasts, and macrogametes were identified within parasitophorous vacuoles of epithelial cells located near the renal corticomedullary junction. The prevalence of renal coccidiosis in P. bougainville diagnosed by renal histology is estimated at 30%. Only a single unsporulated sporocyst was detected by examination of cystocentesis-collected urine, indicating that microscopic evaluation of urine samples is an insensitive diagnostic test for detection of K. quimrensis in P. bougainville. This infection in P. bougainville is indirectly associated with mild multifocal interstitial lymphohistiocytic nephritis and is likely to be only minimally pathogenic in otherwise healthy individuals. Our study also extends the host and geographic range of K. quimrensis to include P. bougainville and Western Australia.

Disseminated cryptococcosis including osteomyelitis in a horse.

A 4-year-old Arab mare was diagnosed with disseminated cryptococcosis, including osteomyelitis of the proximal phalanx of the left hind limb, osteomyelitis with associated soft tissue granuloma of a rib and disseminated, large cryptococcal nodules in the lungs. The lesion in the dorsoproximal aspect of the proximal phalanx had a large area of cortical lysis with spiculated periosteal new bone and extensive soft tissue swelling. The affected rib had a pathological fracture. Cryptococcal osteomyelitis has not been previously reported in horses but should be considered as a differential diagnosis, particularly in endemic regions.

Enzootic pneumonia of pigs--a diagnostic dilemma.

In an enzootic pneumonia-free Australian pig herd, an outbreak of a severe respiratory disease in the grow-out herd was initially diagnosed as acute tracheitis and pneumonia precipitated by the dusty environment, with a superimposed mixed infection of Pasteurella multocida and Arcanobacterium pyogenes. Culture for Mycoplasma hyopneumoniae, Salmonella sp and fungi was negative. The outbreak persisted. Subsequently, gross lesions consistent with enzootic pneumonia occurred, but histological lesions were equivocal and definitive tests for M hyopneumoniae remained negative. Eighteen months after the initial outbreak, gross and histological lesions were consistent with enzootic pneumonia but serological tests were still negative. Almost 2 years later, one of four nasal swabs was positive by the polymerase chain reaction test for M hyopneumoniae, and then lung samples were sporadically positive. The pneumonic disease became endemic in the herd. Gross lesions consistent with enzootic pneumonia occurred in another herd belonging to the same company nearly 2 years after the initial outbreak. Again, results of laboratory tests were inconsistent. Despite sporadic positive polymerase chain reaction tests for M hyopneumoniae, the respiratory disease resolved within 4 months and there has been no clinical evidence of enzootic pneumonia during the subsequent 4 years. These cases raise important questions about the role of the diagnostic tests and their interpretation, and the ecology of M hyopneumoniae and its role in enzootic pneumonia.

Successful management of histiocytic ulcerative colitis with enrofloxacin in two Boxer dogs.

Two Boxer dogs with histologically confirmed histiocytic ulcerative colitis were treated with enrofloxacin, one as sole therapy and one in conjunction with prednisolone, after failure of standard therapy. Clinical remission occurred rapidly in both dogs after commencement of enrofloxacin and in one case where repeat colonoscopy was performed the endoscopic appearance of the mucosa was normal within 2 weeks. Histological examination of the colonic mucosa in this dog after 7 months showed resolution of the cellular infiltration characteristic of histiocytic ulcerative colitis. Histological improvement following therapy in Boxer dogs with histiocytic ulcerative colitis has not been reported previously.

Thoracic actinomycosis (arcanobacteriosis) or nocardiosis causing thoracic pyogranuloma formation in three dogs.

OBJECTIVE: To describe three cases of canine thoracic actinomycosis (arcanobacteriosis) or nocardiosis in which the primary pathological lesion was a pyogranulomatous abscess in the mediastinum. Clinical signs, difficulties in diagnosis, treatment and prognosis are examined. Comparisons are made between human and veterinary literature to assist in formulating a rational treatment plan. DESIGN: Retrospective clinical study. PROCEDURE: Review of case records from 1984 to 1998. RESULTS: Three dogs presented with large intrathoracic pyogranulomas producing variable clinical signs, not necessarily associated with the respiratory tract. Ages ranged from 2 to 5 years old. Two dogs responded to surgical opening and passive drainage of the abscess, or surgical excision of the granuloma with associated structures, and medical therapy. One dog died intra-operatively. CONCLUSION: A combination of surgical and antimicrobial therapy may carry a fair-to-good prognosis for thoracic granuloma caused by actinomycosis (arcanobacteriosis) or nocardiosis. The extent of surgery should be based on assessment of individual cases and must include surgical biopsy for histology and culture to enable a specific diagnosis to be made. Complete surgical excision is not necessarily required. Prolonged antimicrobial therapy is indicated.

Granulosa cell tumour in two speyed bitches.

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.

The spread of transgene expression at the site of gene construct injection.

Seven 2-day-old golden retriever pups were given focal intramuscular injections of a first generation adenovirus-dystrophin minigene construct and adenovirus-beta-galactosidase construct as a 2:1 mixture into the left anterior tibial muscle. The spread of transgene expression within the anterior tibial muscle was compared with the spread of methylene blue dye after identical injection into the contralateral muscle. Transgene expression 5-7 days after intramuscular injection was shown to extend between 5.8 and 11.6 mm along the biopsied muscle length (range of biopsy lengths 11.1-12.2 mm). The level of transgene expression at 2-2.5-mm intervals from the site of injection was significantly related to the distance from the site of injection (dystrophin, P = 0.009; beta-galactosidase, P = 0.015). The spread of methylene blue dye within the anterior tibial muscle < or =24 h after identical intramuscular injection demonstrated a similar pattern to the transgene expression, with dye staining measured between 5.5 and 8.5 mm along the muscle sample length (range of biopsy lengths 5.6-15.6 mm). The greatest transgene expression and dye staining was measured 2-2.5 mm proximal to the site of injection with a maximum of 23% of muscle fibers expressing the dystrophin transgene, 95.2% expressing the beta-galactosidase transgene, and 98% of the tissue section stained with methylene blue dye. These results suggest transgene expression after focal intramuscular injection is relatively localized around the site of injection. Further research is required to develop techniques that will provide transgene expression throughout the length and breadth of a muscle.

Laryngeal rhabdomyoma in a dog.

A 4-year-old spayed female Golden Retriever was presented for investigation of progressive loss of bark, continuous panting and increased upper respiratory noise. Examination of the larynx and pharynx under general anaesthesia identified a spherical 5 x 3 cm mass involving the right arytenoid cartilage. Cytological examination of fine needle aspirates from the mass suggested the tumour was a carcinoma, however histological examination in association with immunoperoxidase and histochemical staining identified the mass as a laryngeal rhabdomyoma.