Stewart, K. L., Guilfoyle, D., Preisser, W. 2013. Increased cage height does not impact the wellbeing of rabbits. American Association for Laboratory Animal Science [AALAS] Meeting Official Program, 665 (Abstract #P159).

In the eighth edition of the Guide for the Care and Use of Laboratory Animals, the recommended rabbit cage height was changed from 14 to 16 in. In contrast, the majority of our rabbit cages, purchased in 1985 after the USDA prescribed rabbit cage size requirements, provide 15 in. of interior cage height. A review of the literature failed to identify published data that support an advantage to rabbits having 16 in. of cage height compared with 14 or 15 in. The study described here evaluated the benefit of this minimal change in cage height for rabbits by comparing the effect of the cage height on the health, growth, and overall wellbeing of the rabbits. Groups of 10 New Zealand white rabbits were housed in cages that provided either 15 or 18 in. of interior cage height. The rabbits were observed for 25 1-h periods over 7 wk and various behavioral parameters scored. In addition, rabbits were weighed weekly and general clinical health assessed. After 4 wk, the groups were switched to the alternate housing. No significant differences were observed in body weight gain or behavioral parameters between groups housed in cages of different heights, nor were significant differences observed in groups of rabbits when moved from one cage type to the other. In addition, all rabbits remained clinically healthy through the course of the study. These results demonstrate that minimal changes in interior cage height neither benefit nor harm rabbits.