The long-term skeletal effects of EHDP in dogs.

Disodium hydroxymethanediphosphonic acid was administered subcutaneously (s.c.) to adult beagle dogs for 1 to 2 years at various dose levels to determine its skeletal effects when given chronically. The effects were followed densitometrically, radiographically and by making histomorphometric measurements in sequential rib biopsies. At low doses (0.1 and 0.5 mg/kg/day s.c.) EHDP caused a time-and-dose dependent reduction in the percentage of bone surfaces with active mineralization, a reduction in mineralization rates, a reduction in resorption spaces but no changes in osteoid seam widths. No treatment related bone fractures were noted at the 0.1 mg/kg/day level, while at 0.5 mg/kg/day, fracture incidence appeared slightly increased. At higher doses (2-10 mg/kg/day), there was also a reduction in the number of resorption spaces, but mineralization activity was totally blocked, osteoid seams became thickened and fracture incidence was markedly increased. In one group of animals, EHDP treatment was discontinued after one year of dosage at 5 mg/kg/day given subcutaneously. In these animals, mineralization activity reappeared within 3 months, but osteoid seams remained thickened until 7 months post-treatment. These data indicate that EHDP can have profound effects on bone remodeling in the dog but that these effects are dose-and-time-dependent and they appear to be reversible.

Lymphosarcoma with lymphoblastic leukemia in a New Zealand white rabbit.

An 8 to 10-week-old female New Zealand white rabbit, Oryctolagus cuniculus, which exhibited clinical signs of anorexia, depression, and torticollis was found to have lymphosarcoma with lymphoblastic leukemia. The multiple visceral involvement with neoplastic lymphoid cells observed in this animal was similar to previously reprted cases of lymphosarcoma in the rabbit. An unusual finding was the occurrence of lymphoblastic leukemia since lymphosarcoma in the rabbit has previously been reported as aleukemic.

Chronic bile duct cannulation of rhesus macaques (Macaca mulatta) without causing biliary fistulas.

Two surgical procedures were used for establishing chronic bile duct cannulations in rhesus macaques (Macaca mulatta) while maintaining an intact enterohepatic circulation for use in metabolism studies. One procedure resulted in the formation of biliary fistulas in all of the animals, whereas the other procedure allowed successful maintenance of the macaques without fistulation for up to 8 months after surgery. The possible importance of pressure against bile outflow in the development of the fistulas was discussed.

Facial alopecia in the rabbit associated with Cheyletiella parasitivorax.

A facial dermatitis characterized by alopecia over the frontal area with varying degrees of erythema and scale formation was observed in 46 newly arrived New Zealand White rabbits within a 5-month period. The clinical history, nature of the lesion, and laboratory findings indicated that the mite Cheyletiella parasitivorax was the most likely cause of the dermatitis.

Technic for serial bone sampling in canine skeletal labeling studies.

A technic was described for repetitive bone sampling in beagle dogs. The procedure has provided ideal samples for quantitative histologic technics following 135 biopsies.