Experimental scrapie in white Swiss mice.

In order to confirm the clinical and histological diagnosis of scrapie and to determine the infectivity titer of the scrapie agent in the brain of a naturally infected Suffolk sheep, 123 white Swiss mice were inoculated intracerebrally. From about 13 to 20 months post-inoculation, 28 mice died, and 95 that were sick were killed. In the terminal stages of disease, the mice developed weakness, gradual emaciation, posterior ataxia, and occasionally alopecia.

Larval parasites in lymph nodes of slaughter cattle.

Between 1977 and 1989, evidence of parasitic infection was found in lymph node sections of twelve cattle (0.5 per cent of lymph nodes) submitted by Canadian federal meat inspectors under the tuberculosis eradication program. Macroscopically, all lesions were green foci of various sizes; microscopically, parasitic larvae were surrounded by a wide zone of eosinophils.

Melanocytic cutaneous lesions and melanotic regional lymph nodes in slaughter swine.

During a five month period, 220 slaughter swine (at two abattoirs) had gross cutaneous and lymph node lesions suggestive of melanoma. Lymph nodes from 214 and cutaneous lesions from 176 of these pigs were submitted for histological examination. Of the cutaneous lesions, 174 were spontaneously regressing melanomas, and two were nonregressing.

Adenocarcinoma of the salivary gland in a white Swiss mouse.

A salivary gland adenocarcinoma in a white Swiss mouse used in a titration of the scrapie agent is reported. The neoplasm originated from the serous cells of the parotid salivary gland. Retroviral particles were detected in the neoplastic salivary gland cells by electron microscopy.

An outbreak of cysticercosis in feedlot cattle.

An outbreak of cysticercosis (infestation with the larvae of Taenia saginata) occurred in feedlot cattle in Ontario in 1986. Two hundred and thirty-three of 271 steers were confirmed histologically to be positive for cysticerci. Nineteen (8.

Experimental peste des petits ruminants (goat plague) in goats and sheep.

In order to study the pathomorphology and immunohistochemistry of peste des petits ruminants, four goats and two sheep were inoculated intranasally with the Malig-Yemen strain of peste des petits ruminants virus. The animals developed fever, nasal discharge, oral erosions, cough and diarrhea. One goat and one sheep died and one moribund goat was killed.

Comparison of spongiform lesions in experimental scrapie and rabies in skunks.

Striped skunks were inoculated intracerebrally with the scrapie agent (suspension of brain from a naturally infected Suffolk sheep) or intramuscularly with street rabies virus (suspension of salivary glands from naturally infected skunks). Those given the scrapie agent developed clinical signs of weakness, posterior ataxia, and emaciation after incubated periods of 8 to 23 months. Those inoculated with rabies virus developed clinical signs of rabies (aggressive behavior, hyperexcitability, ataxia and paralysis) after incubation periods of 20 to 62 days.

Experimental rabies in skunks and foxes. Pathogenesis of the spongiform lesions.

The pathogenesis of rabies spongiform lesions in striped skunks (Mephitis mephitis) and red foxes (Vulpes vulpes) was studied by light and electron microscopy and peroxidase-antiperoxidase immunocytochemistry. Studies in skunks included use of several street virus variants (different antigenic profiles as tested by monoclonal antibodies) different routes of inoculation (intranasal, intracerebral and intramuscular), immunosuppression of infected skunks, different preparations of virus (brain and salivary gland suspensions and infective tissue culture fluids), and sequential development of the lesions. Foxes (Vulpes vulpes) were infected intramuscularly with a street virus isolate.

Necrobacillary bronchopneumonia in a steer.

A one and one-half year old steer killed in a slaughterhouse had necrobacillary fibrinous bronchopneumonia with abscessation. Histologically, there were variably sized areas of coagulation necrosis in the lungs, thrombosis of pulmonary lymphatics, and fibrin deposits in the bronchioli and adjacent alveoli. Fusobacterium necrophorum in pure culture was isolated from the lung.

Mycotic lymphadenitis in cattle and Swine.

Lymph nodes with granulomatous mycotic lesions from 100 cattle and 9 pigs were examined. More than 90% of cases of mycotic lymphadenitis in cattle occurred in the mesenteric nodes, whereas in swine lesions occurred at multiple sites. All observed mycotic infections were caused by zygomycetes.

Arteriosclerosis in seven cattle.

Sporadic arteriosclerosis of the aorta, with or without pulmonary ossification, occurred in seven cattle from slaughter-houses and farms. Aortic walls were thickened, and had many white or yellow mineralized plaques on the intimal surface. The lungs did not collapse, were firm, gritty and crepitant on palpation, and sponge-like in appearance on cross section.

Sheep pox: experimental studies with a west african isolate.

Under conditions of a maximum security laboratory, four cross-bred sheep were inoculated intradermally only or intradermally and intratracheally with a West African isolate of sheep pox virus. All sheep had increased temperature and depression by the fourth or fifth day after infection. Nasal and lacrimal discharge and coughing occurred in all sheep but were more severe in sheep receiving the virus via the tracheal route.

Peripheral nerve sheath neoplasms in canadian slaughter cattle.

Two thousand four hundred and fifty-six bovine neoplasms were submitted during a ten year period of which 238 (9.7%) were neurofibromas. The neoplasms were mainly in the heart but also in the thorax, mediastinum and in some visceral organs.

Primary Hepatocellular Tumors in Animals Killed at Meat Packing Plants: Report of 11 cases.

Eight bovine, two ovine and one porcine primary hepatocellular neoplasms were found during a five year survey of tumors from meat packing plants. The tumors varied in size and usually were yellow-grey. Some were encapsulated and divided into lobules by fibrous septa.

Primary salivary gland neoplasia in three cows.

Salivary gland neoplasms in cattle are rarely reported. Three parotid gland carcinomas from slaughter cows are described. Based on light microscopic and ultrastructural appearances the neoplasms were classified as pleomorphic carcinomas in Cows 1 and 2 and as a squamous cell carcinoma in Cow 3.

Acute anaplasmosis in imported cattle.

Of 18 Hereford cattle imported into Quebec from the eastern U.S.A.

Copper toxicosis in lambs fed milk replacer.

Thirty-four hysterectomy derived, crossbred lambs were fed a commercial, lamb milk replacer, containing added copper from birth. Twenty-five lambs died, four were killed and five survived. At necropsy, generalized icterus, enlarged kidneys and enlarged or small livers were found.

Feline Cutaneous Phaeohyphomycosis Caused by Phialophora verrucosa.

A cutaneous granuloma which developed on the muzzle of a nine year old cat was shown by histopathology to have been caused by a dematiaceous fungus which was cultured and identified as Phialophora verrucosa.

Bovine neoplasms encountered in Canadian slaughterhouses: a summary.

During the past five and one half years veterinarians of the Food Production and Inspection Branch of Agriculture Canada submitted tissues from 1535 cases of suspected bovine neoplasia for diagnosis to the Animal Diseases Research Institute, Nepean. Neoplasia was confirmed in 1370 cases. Lymphosarcoma was diagnosed in 738 (53.