Blood supply to the periosteum of the canine tibia.

A study was undertaken to determine which arteries supply the periosteum of the normal adult canine tibia. The vessels were found to arise from locations distinct from the muscular vascularization. The venous drainage of the tibial periosteum had a satellite relationship with the arteries. On the surface of the periosteum, the vessels formed rectangular patterns. All surfaces of the distal end of the tibia seemed to have less distinct anastomoses of the transverse periosteal twigs, compared with the proximal end of the tibia.

Radiographic examination of mandibular lesions in barren-ground caribou.

Dental anomalies were observed in 43 of 1,226 barren-ground caribou (Rangifer tarandus groenlandicus) taken between 1966 and 1968. In five of these 43 animals, the mandibles had deformities which radiography showed to be the result of dental abscesses in four cases and probably of a trauma in the other. The absence of actinomycotic lesions of the jaw bones of these 1,226 animals, and of more than 500 examined previously, indicates that "lumpy jaw" is rare in barren-ground caribou. The authors suggest the use of radiography to determine the nature of bone growth on skeletal remains, in the absence of soft tissues for examination for Actinomyces, either microscopically or by cultural methods.

Changes in the acid base status of sheep anaesthetised with a combination of atropine sulphate acepromazine and ketamine hydrochloride.

pH, PaCO2, PaO2, standard bicarbonate, base excess and reduced pH were measured in sheep before and at regular intervals after administration of ketamine with and without atropine and acepromazine premedication. A decrease in pH and PaO2 and a rise in PaCO2 was observed 15 minutes after administration of ketamine. Administration of atropine with and without acepromazine had no significant effect on pH, PaCO2 and PaO2. The values for standard bicarbonate, base excess and reduced pH were not significantly affected. This indicates that minor changes observed in pH, PaCO2 after ketamine administration are compensated for by the healthy animal's blood buffer system.

Polydactylism in a white-tailed deer from eastern Ontario.

A polydactylous right front foot was collected from a white -tailed deer (Odocoileus virginianus) fawn in eastern Ontario, Canada. We determined by gross visual and radiographic examinations that the polydactylous foot had a complete extra digit in the position of the ancestral 1st digit. This is the first documented account of a perfect polydactylous condition in a North American cervid.