Love, J. A., Hammond, K. 1991. Group-housing rabbits. Lab Animal 20(8), 37-43.

The management and success of a group-housing indoor/outdoor pen system for rabbits [mainly females] is described and discussed. Over a three-year study period a total of 141,000 rabbits were included in the assessment. The levels of fighting injuries was low, and considered acceptable. ... Castrating males before reaching puberty resolved this problem [injurious fighting among males]. ... There was no evidence that infectious disease spread was a problem among the group-housed rabbits. ... There were no clinical cases of trichobezoars in the group-housed rabbits. Several factors - lack of exercise, lack of roughage, pathologic grooming due to isolation - are implicated in the formation of trichobezoars, and the group-housing system took these into account. ... Group-housing rabbits requires the ability to recognize the signs of an unwell animal. Adding treats like hay to the diet helps, as does the weekly health check. These checks become routine every time technicians handle the rabbits, and do not require much time.