Dermatologic Investigation of Alopecia in Rhesus Macaques (Macaca Mulatta)

In 2005, a study involving 183 rhesus macaques at the German Primate Center found that 126 (68.9%) of these animals suffered from partial to complete alopecia, with the majority displaying symmetric hair loss on the back and extremities. Clinical evaluations, including hematologic, bacteriologic, mycologic, parasitologic, and histopathologic assessments, were conducted. The results showed neutrophilia and lymphopenia, slight orthokeratotic hyperkeratosis, and perivascular dermatitis, but no direct correlation with the severity of alopecia. Infectious agents, immunologic causes, nutritional deficiencies, endocrinopathies, psychogenic alopecia, and telogen effluvium were all ruled out as causes. The study concluded that environmental and behavioral factors might be responsible for the hair loss observed in these captive macaques and suggested further research to identify the specific factors affecting hair follicle activity.