Minkel, R. 2007. Pair-housing eliminates compulsive hair pulling: a case report. Laboratory Animal Refinement and Enrichment Forum (electronic discussion group), September 27, 2007.

At a previous institution we had a cyno who suffered from severe hair pulling. He had removed practically all hair from his body; all that was left was a patch in the middle of his back that he could not reach! He was not shy about hiding his idiosyncratic behavior at all and would contort into strange positions to do it. The veterinarians tried various treatments to alleviate the problem to no avail. We tried all the various enrichment devices we could find; they would only keep him occupied for a day or so. We pulled all the dividers from his cage to give him more space; no luck. We were reluctant to pair him as he was an older male who had been singly housed for so long, but there was no other treatment option left.We tried two unsuccessful pairings and finally settled on a newly acquired juvenile male who was very rowdy and active (Grandpa was quite the opposite: relaxed and sedate). The little guy, himself was on his second pair attempt. During his first attempt all he did was try to start a fight. To our great relief the new pair worked out just fine. This truly "odd couple" got along great from the start. Grandpa responded correctly, brought the little guy in line, and actually perked up. The most surprising part, however, was that Grandpa stopped hair pulling. He stopped completely, and all his hair had grown back in the course of several months.Three years later Grandpa had not resumed his old habit, even though his buddy had been removed for research-related reasons one year after the original pair formation.