West, A. M., Leland, S. P., Lorence, M. A. et al. 2008. Behavioral correlates of alopecia severity in laboratory rhesus macaques (Macaca mulatta). American Journal of Primatology 70(S1), 51. (31st Meeting of the American Society of Primatologists Scientific Program, Abstract #93)

Alopecia in laboratory primates is often regarded as a sign of excessive self-grooming due to social deprivation or insufficient environmental enrichment. The purpose of this study was to examine, in individually housed macaques, the occurrence of alopecia in relation to grooming and other behavioral patterns. Twenty-four rhesus macaques (Macaca mulatta) were selected based on differing patterns of alopecia. Eight exhibited no alopecia and served as the Control Group (CG). Eight exhibited bilateral symmetrical alopecia (BS), and eight exhibited less severe, asymmetrical alopecia (AS). Each animal was observed for 39 minutes over a 10-day study period. Observations lasted three minutes, and all were conducted in the afternoon. The behavioral patterns observed included the following: self-grooming, cage contact, scratching, foraging, enrichment manipulation, and manipulation of foraging feeders. Contrary to expectation, mean rates of self-grooming did not differ significantly [Mann Whitney U Test; α=0.05] across the groups (CG=3.0%; AS=4.1%; and BS=2.2%), so alopecia, at least in this situation, clearly did not result from “over-grooming.” The only behavioral pattern that was significantly related to severity of alopecia was “cage contact.” Severity of asymmetric alopecia was highly correlated with amount of cage contact [Spearman’s ρ =+0.74; p<0.05; n=8 pairwise comparisons]. The location of alopecia was always the same part of the body as was commonly in contact with the cage, suggesting that lateralized alopecia resulted from cage contact, not excessive self-grooming.