Canadian journal of comparative medicine and veterinary science最新文献

A five and one-half year old deer (Odocoileus virginianus) developed an ankylosing periarticular hypertrophic arthritis due to a coagulase positive staphylococcus infection. Complete encasement of the tibio-tarsal (hock) joints with a hypertrophic, and porous osseous mass had occurred with complete loss of articular cartilage. The pathologic alterations of the tissues are compared to those occurring in swine due to Erysipelothrix insidiosa infection which produces a rheumatoid-like arthritis.

A convenient technique is described for the preparation and surgical implantation of permanent cannulae into the lateral ventricles of the rat brain, as well as a method for radiographic confirmation of the location of the implanted cannula. The modified implantation method described is simple, rapid and has produced low mortality in the surgically altered animals.

Free amino acid pattern has been studied in rice moth larvae during aflatoxicosis and compared with normal in ground nut meal and wheat bran. It was observed that there is an increase in free amino acids in intoxicated larvae and this was directly proportional to the degree of toxicity as indicated by decrease in growth of these larvae. The study of excretary pattern of amino acids shows that intoxicated larvae excrete less amino acids than the normal larvae. The results have been discussed.

Serial ova count studies were conducted to determine some of the characteristics of the spring rise in faecal shedding of nematode ova by parasitized sheep in flocks in the Montreal area. It was discovered that substantial spring rises occurred in most ewes following their lambing but that great variation existed in the magnitude, duration, and pattern of the rises. Although rams did not display increased ova counts, a slight but well-defined rise developed in one unbred ewe. Larval studies in ewes parasitized by a variety of nematode species, revealed that Haemonchus contortus was the major contributor to the spring rise in faecal ova output. Preparturient treatment of ewes with thiabendazole(1), at the rate of 100 mg./kg. of body weight, suppressed spring rise but failed to arrest completely the faecal shedding of nematode ova.

Nine white-tailed deer and six sheep were experimentally exposed to the California BTV-8 strain of bluetongue virus. The infections were fatal for seven of the nine deer. An additional deer died from exposure to an isolate of bluetongue virus from bighorn sheep. Clinical signs and lesions of bluetongue in deer were described. The incubation period, signs and lesions of bluetongue and epizootic hemorrhagic disease of deer appear to be similar. Virus isolations were made from the blood and a variety of tissues of exposed deer and identified as bluetongue virus. Neutralizing antibodies were detected in all of the convalescent sera.

A practical culture medium which allows direct plating of milk samples for detection and differentiation of Streptococcus agalactiae within 48 hours is described. Most other micro-organisms likely to be present in these samples are inhibited. Although some strains of Staphylococcus species and ofStreptococcus faecalis are able to grow, they may be differentiated on the basis of reaction in the medium surrounding the colonies.

Inoculation of the udders of cows with the virus of enzootic abortion of ewes resulted in a severe acute mastitis. The mastitis was characterized clinically by pyrexia, anorexia, decreased milk production, swelling and marked alteration in the physical quality of the milk. The basic lesion was necrosis of alveolar and duct epithelial cells. Virus particles were demonstrated in all levels of the mammary gland three days after inoculation illustrating the rapid spread of the agent. Cells resembling Reed-Sternberg cells and similar to those seen in experimental mastitis produced by the virus of infectious bovine rhinotracheitis were seen in tissues collected six and nine days after inoculation.

Eight adult deer and 4 fawns, from wild populations, were splenectomized and observed for evidence of hemo-parasitic relapses. The animals were maintained indoors under tick-free conditions and in the absence of known arthropod vectors. Following splenectomy 2 adult deer and 2 fawns developed acute Eperythrozoon infections, 3 adult deer developed acute Theileria infections, 2 adult deer developed a demonstrable Anaplasma marginale parasitemia, and 1 adult deer exhibited a low level parasitemia of a plasmodial-like intraerythrocytic parasite. The remaining deer failed to develop a parasitemia following splenectomy. In the absence of a specific parasitemia no drop occurred in packed cell volume following splenectomy.

Mastitis was produced in three first calf heifers by inoculation of the udder with the virus of infectious bovine rhinotracheitis. These animals were killed at different times during the course of the disease and tissues were harvested and examined histologically. The basic lesion resulted from the necrotizing effect of the virus upon the epithelial cells of the alveoli and ducts. Eosinophilic intranuclear inclusion bodies were demonstrated in tissues from animals killed at three and six days postinoculation, but not at nine days. Of interest was the presence of a large Reed-Sternberglike cell in tissues of the last two animals killed.

An apparent relationship between locoism and lathyrism was investigated. Similarities reported in the literature in botanical relationship, signs produced in affected animals, and chemical characteristics were noted. It was demonstrated that the known lathyrogens, aminoacetonitrile and alpha, gamma-diaminobutyric acid, as well as an extract from the loco plant (expected to contain lathyrogens if present in the plant) produced many of the abortive, teratogenic and neurologic effects and signs evident in animals in true locoism. Preliminary assay of extracts from the plant suggested the presence of lathyrogens in the loco plant.