Effect of cage size on patterns of activity and health of beagle dogs.

Thirty-two male beagle dogs were assigned at random, 16 to standard size cages (30 X 30 X 30 inches) and 16 to large cages (90 X 30 X 30 inches) for a period of 13 weeks, and then were "crossed-over" for an additional period of 13 weeks. The dogs were observed daily and weighed weekly. Electrocardiographic and ophthalmologic examinations were made once and hematologic and biochemical measurements were made twice during the control period and at monthly intervals during the study. Photographs were taken of each dog every 60 seconds, 7 days a week, for about 8.5 hours each day. The film was processed and analyzed for the acf standing sitting, lying, or sleeping. In addition, dogs in the large cages were scored for the region (front, middle, or back) occupied. No statistically significant differences were found between dogs in the standard or large cages with respect to weight gain, percent of time standing, and percent of time sleeping. Statistically significant (p less than 0.05) differences were found for percent of time sitting (standard cages 12.7%; large cages 9.4%) and percent of time lying (standard cages 6.6%; large cages 8.3%); however, the differences were not large enough to be of any practical concern. Transient patterns of response over 13-week periods of the study were essentially the same (statistically verified) for dogs in either size cage. Also statistical results showed that there was no significant carryover (residual) effect associated with any of the parameters measured. No beneficial or adverse effects were noted that could be related to the size of the two cages. The size of the standard cage appeared adequate for laboratory beagle dogs and no advantage was found when the dogs were in larger cages with respect to behavior, patterns of activity, or health.

Dimethyl sulfoxide: lens changes in dogs during oral administration.

Oral administration of dimethyl sulfoxide to young dogs reduces relucency of the lens cortex, causing the normal central zone of lens to act as a strong biconvex lens.