Alopecia in rhesus macaques (Macaca mulatta): Association with pregnancy and chronic stress

Background Alopecia in captive non-human primates is often presented as a welfare issue. However, it is a complex condition with a number of possible causes. The purpose of this study was to assess the impact of pregnancy and hair cortisol concentrations on alopecia in rhesus macaques. Methods Subjects were 113 socially housed adult female rhesus macaques (27 pregnant, 35 nursing infants, 51 controls). During routine physicals, photographs were taken for alopecia assessment and hair samples were collected for cortisol assay. Results Alopecia was more prevalent in pregnant than in control females, but there was no association between alopecia and hair cortisol. However, there was a significant effect of pregnancy on hair cortisol. Nursing females had higher hair cortisol levels than pregnant females, which had higher levels than control females. Conclusions Although alopecia does not appear to be associated with hair cortisol, both alopecia and hair cortisol were associated with pregnancy.