Acute sarcocystosis-like disease in a dog.

Two of 8 littermate Rottweiler dogs developed persistent diarrhea at 6.5 weeks of age. Dog 1 was euthanatized at 14 weeks of age and had hepatitis characterized by necrosis and mixed leukocyte infiltrations in association with a previously unrecognized Sarcocystis-like protozoon. The organism was free in the hepatocyte cytoplasm without a parasitophorous vacuole, had divided by schizogony, and stained with anti-Sarcocystis serum, but did not stain with anti-Toxoplasma gondii or anti-Neospora caninum serum in an immunohistochemical test. Dog 2 was euthanatized at 10 weeks of age. This dog had large necrotic, hemorrhagic mesenteric lymph nodes. Numerous T gondii tachyzoites were observed in association with these lesions. The organism divided by endodyogeny and stained specifically with anti-T gondii serum.

Generalized nodular dermatofibrosis and renal cystadenocarcinomas in a German shepherd dog.

Generalized, nodular dermatofibrosis with coexisting bilateral renal cystadenocarcinomas was diagnosed in a 6-year-old male German Shepherd Dog. Approximately 3 years earlier, the dog had been examined because of lameness attributable to 2 nodular growths between the third and fourth digits of the right front limb. Biopsy revealed dense collagenous dermal fibrosis, often in a nodular arrangement. As the disease progressed, attempts to alleviate the discomfort and lameness caused by the nodular growths were performed by surgical excision. During this period, other nodular growths that developed apparently did not bother the dog. Because of the long and protracted clinical progression of the disease and poor prognosis for successful treatment, the dog was euthanatized. At necropsy, multiple multicentric nodules were found in the skin and subcutis, with most located on the limbs. The nodules were well-circumscribed and hard. Epithelial ulceration and inflammation were confined to nodules on the feet. Small foci of collagenous proliferation were found along fascial planes. In addition, cystic neoplasms were in both kidneys. The microscopic diagnosis was generalized nodular dermatofibrosis, with bilateral renal cystadenocarcinomas.

Leiomyosarcoma of the canine urinary bladder, with metastases.

An enlarged nodular mass, assumed to be the prostate gland because of location and consistency, was palpated in the pelvic region of a 10-year-old German Shepherd Dog. Castration was performed as a therapeutic procedure after an estrogenic hormone failed to reduce the size of the mass. A tumor identified histologically as a seminoma was in the right testicle. The dog died 1 month after castration, and generalized metastatic neoplasia was observed at necropsy. The mass that involved the neck of the bladder and the metastases were identified as leiomyosarcoma.