Bacillus piliformis infection in an adult dog

Bacillus piliformis infection (Tyzzer's disease) was diagnosed in a 7-year-old spayed dog that had icterus, hepatosplenomegaly, and polyuria. Hematology revealed regenerative anemia, leukocytosis, lymphopenia, and thrombocytopenia. Serum chemical analyses indicated hypocalcemia, high alkaline phosphatase activity, hypoalbuminemia, and hyperglobulinemia. At necropsy, the liver was stippled with gray-white focal lesions. Microscopically, the liver lesions were necrotic and inflammatory. Warthin-Starry-stained sections revealed rod-shaped bacteria in crisscrossing patterns characteristic of B piliformis. This dog was considerably older than dogs previously reported to have Tyzzer's disease and had a concurrent systemic hyphomycosis, suggesting it had been immunocompromised.     

Primary pulmonary artery leiomyosarcoma in an adult dog

A 7-year-old neutered female English Setter presented with syncope, anemia, and weight loss. Clinical examination revealed a systolic murmur and echocardiography demonstrated a mass on the pulmonic valve. Postmortem examination confirmed the presence of a pulmonic valve mass that extended along the pulmonary trunk and into the left pulmonary artery. Multiple pale nodules were observed in the right lung. Microscopic examinations of the pulmonary artery mass and the lung nodules revealed a pleomorphic population of spindle cells often arranged in broad bands containing strap-like nuclei and eosinophilic cytoplasm devoid of cross striations. The neoplastic cells expressed vimentin and alpha-smooth muscle actin but did not express desmin, CD31, factor VIII, or S100. The presentation, histological features, immunocytochemical profiles, and behavior of this tumor were indicative of a primary pulmonary artery leiomyosarcoma with lung metastasis.     

Intestinal malabsorption and cryptosporidiosis in an adult dog

Chronic intestinal cryptosporidiosis was diagnosed as the cause of chronic diarrhea and weight loss in an adult dog without obvious signs of immunosuppression. Results of tests for digestive function suggested that the dog had impaired intestinal absorption or bacterial overgrowth. The nutrient malabsorption might have resulted in or have been caused by the cryptosporidiosis. Temporary clinical improvement without reduction in fecal oocyst concentration was noticed following treatment with clindamycin. The dog was euthanatized. At necropsy, the dog was found to have chronic lymphoplasmacytic enteritis and cryptosporidiosis. A veterinary student that worked in the ward where the dog was kept developed cryptosporidal diarrhea.     

Treatment of renal nephroblastoma in an adult dog

An 8-year-old Labrador retriever was diagnosed with a unilateral malignant nephroblastoma and hypertrophic osteopathy. The histopathologically malignant tumor was confined to the renal capsule, but the sarcomatous component was anaplastic, resulting in its classification as a Stage I tumor with unfavorable histopathology. The dog was treated with unilateral nephrectomy, vincristine, and doxorubicin. This dog has remained disease free for >25 months. Reported treatments of renal nephroblastoma in the dog have not described disease-free intervals of >8 months.     

Surgical stabilization of an occipitoatlantoaxial malformation in an adult dog

Objective: To report surgical planning, technique, and outcome of stabilization surgery in an adult dog with occipitoatlantoaxial malformation (OAAM). Study Design: Clinical report. Animal: A 19‐month‐old, 25.5 kg, male castrated, Shiba Inu. Methods: Radiographic and magnetic resonance imaging were used to identify and characterize OAAM. Using a ventral approach to the cranial cervical region 2 cortical bone screws were inserted from the axis into the malformed atlas and occiput. Results: Ambulation was conserved postoperatively. Within 4 weeks, neurologic examination was mostly normal except for decreased proprioception in the right pelvic limb. At 9 months, the dog retained an extended neck posture, but had no neurologic abnormalities. Conclusion: OAAM should be considered as a differential diagnosis in an adult dog with cervical myelopathy. Surgical fixation with cortical bone screws using a ventral approach can be successful.     

Gastro–oesophageal intussusception in an adult dog

A case of oesophageal intussusception of the stomach in a 9–year–old 351b cross–bred male dog is reported. This condition has previously been recorded only in young animals, often in the first few weeks of life. The history and post mortem findings are described, the aetiology is discussed and the literature briefly reviewed.     

Dermal melanocytoma-acanthoma in an adult mixed breed dog

A cutaneous melanocytoma-acanthoma was diagnosed in a 7-year-old intact female mixed breed dog. Grossly, this tumor was a solitary and darkly pigmented nodule located in the face. Histologically, the lesions consisted of melanocytic and epithelial tumor cells. The melanocytic component consisted predominantly of large round-to-polygonal and heavily pigmented melanocytic cells arranged in nests and clusters. These melanocytes were positive for S-100 and vimentin. The epithelial component was composed of multiple small horn cysts with concentric keratin within the cyst lumina and was positive for cytokeratin. Atypism was not observed in both components. Since this tumor has previously been reported in only two dogs, this report adds to the data that will help determing predilections of age, breed, sex and site.     

Neosporosis with cerebellar involvement in an adult dog

A case of an adult dog with multifocal, progressive neurological signs caused by Neospora caninum is reported. Pathological studies showed cerebellar lesions due to the parasite, which was also present in other parts of the nervous system and muscle. Cerebellar atrophy related to Neospora infection has been rarely reported in veterinary medicine, and has been shown to affect ruminants and dogs. The cerebellar involvement and the age of the present dog make this case uncommon.     

Idiopathic, duodenogastric intussusception in an adult dog.

An adult Basset Hound was examined because of acute vomiting, signs of depression, dehydration, and signs of abdominal pain. Radiography revealed a soft tissue dense mass in the stomach. At exploratory laparotomy, 75% of the stomach was black, and the pylorus, proximal portion of the duodenum, and pancreas were found inverted into the stomach. The dog was euthanatized.     

Neospora caninum associated with septic peritonitis in an adult dog

A 7-year-old, male neutered Rhodesian Ridgeback dog was referred to the University of California-Davis Veterinary Medical Teaching Hospital with a 4-month history of peritonitis and episodic abdominal discomfort, lethargy, and weakness. Marked abdominal distension with a prominent fluid wave was noted on physical examination. Cytologic analysis of the abdominal fluid indicated a septic exudate with mixed bacteria and many protozoal zoites. Differentials for the identity of the protozoal zoites included Toxoplasma gondii, Sarcocystis neurona, and Neospora caninum. Indirect latex agglutination antigen testing, standard indirect fluorescent antibody testing, and PCR analysis were performed to identify the zoites. The dog's serum antibody titer for N caninum tachyzoites was 1:20,480, known polysera to N caninum reacted against zoites in the abdominal fluid, and PCR analysis of the abdominal fluid was positive for the presence of a known gene of N caninum. Based on the morphologic, immunologic, and molecular findings, the zoites were identified as N caninum. It remains unclear how the tachyzoites gained access to the peritoneal cavity. To the authors' knowledge, there are no reports of free N caninum in abdominal fluid of any species.     

Hypertrophic osteopathy associated with infective endocarditis in an adult boxer dog

A 20-month-old, entire male boxer dog was presented with lethargy and intermittent shifting limb lameness. Diagnostic tests revealed aortic valve vegetations suggestive of infective endocarditis causing severe aortic outflow obstruction, and hypertrophic osteopathy of all four limbs. The dog was treated symptomatically and euthanased four days later. The association of infective endocarditis and hypertrophic osteopathy has been poorly documented in the veterinary literature. The pathogenesis of hypertrophic osteopathy is unknown; however, four theories have been put forth to explain this disease: pulmonary shunting, vagal nerve stimulation, humoral substances produced by neoplastic cells and megakaryocyte/platelet clump hypothesis.     

Segmental aplasia of uterine body in an adult mixed breed dog.

Segmental aplasia of the uterine body was diagnosed in a 5-year-old, mixed breed bitch. Abdominal radiography and transabdominal ultrasonography revealed marked dilation of fluid-filled uterine horns with no evidence of a uterine body. Sex hormone assays did not detect the presence of estradiol-17 beta; however, progesterone (2 ng/ml) was found in the serum, indicating anestrus. On gross examination of the reproductive tract, the uterine body was absent, apparently never formed. In its place, a cord-like piece of tissue was identified as an aplastic/dysplastic remnant, connecting the cervix and right uterine horn. The tip of the cord-like piece branched into 5 string-like pieces of tissue, 1 of which was connected to the region dividing the left and right uterine horns. Both the uterine horns were dilated markedly revealing hydrometra. Histologically, uterine body remnant tissues from the endometrium, myometrium, and perimetrium were detected in proximal and distal parts of the uterine body. The string-like piece of tissue connecting the uterine body remnant and the uterine horn consisted of a round cluster of smooth muscle cells surrounding a central core of adipose tissue with blood vessels. It was concluded that the hydrometra observed in both uterine horns was induced by an obstruction resulting from segmental aplasia in the uterine body. This is the first known report of segmental aplasia in the uterine body of a bitch.     

Renal osteodystrophy with facial hyperostosis and 'rubber jaw' in an adult dog

A nine-year-old male Sheltie dog was presented with bilaterally symmetrical maxilliary swelling, loose teeth and flexible mandibles. The condition was progressive over a period of two months. Biochemical and histopathological examinations supported a diagnosis of renal osteodystrophy with facial hyperostosis and 'rubber jaw'.     

Acute primary canine herpesvirus-1 dendritic ulcerative keratitis in an adult dog

We present a report of dendritic ulcerative keratitis in a 4-year old locally immunosuppressed dog suspected to result from acute primary canine herpesvirus-1 (CHV-1) infection. The dog was presented for evaluation of mild blepharospasm and conjunctival hyperemia in the right eye (OD) shortly after attending a public boarding facility. For approximately 3 months, the dog had been receiving topical prednisolone acetate 1.0% and tacrolimus 0.02% in both eyes (OU) q12h for treatment of follicular conjunctivitis. Ophthalmic examination revealed three regions of corneal fluorescein retention OD. The lesions had a dendritic pattern, were approximately 2-3 mm in length, and were located at the dorsomedial, lateral, and ventromedial aspects of the cornea. No additional abnormalities were noted on complete ophthalmic and physical examinations. CHV-1 was identified in conjunctival samples OD by polymerase chain reaction, and paired CHV-1 serum virus neutralization antibody titers were positive and consistent with acute infection. Topical prednisolone acetate and tacrolimus were discontinued. The dog was treated with cidofovir 0.5% OU q12h for a period of 4 weeks, with resolution of corneal disease noted within 1 week of treatment. In conjunction with previous studies, this case report supports a central role for alterations in host immune status in the pathogenesis and clinical manifestations of CHV-1 ocular disease in dogs.     

Hypocalcaemia due to nutritional calcium deficiency and hypoparathyroidism in an adult dog

A 13-year-old intact male poodle had suffered periodic tetanic crises for two months. It was cachectic and moderately dehydrated, and during the crises blindness, a stiff gait and behavioural changes were observed. Routine haematological and biochemical profiles showed that it was severely hypocalcaemic, with a corrected plasma calcium concentration of 1.13 mmol/litre (reference range 2.25 to 3 mmol/litre). The dog was fed a home-made diet composed of chicken and basmati rice cooked with a soup bouillon cube; an analysis of its daily allowance indicated that the dog was generally malnourished and received only 0.222 g of calcium per day rather than the 0.6 g it required. In addition, the dog had a low blood concentration of parathyroid hormone of 12 ng/litre (reference range 20 to 80 ng/litre). Supplementing the dog with calcitriol for four days and correcting its diet increased its blood calcium to the lower part of the reference range and resolved the clinical signs, although its parathyroid hormone concentration was still low one year later.