Evaluation of the use of primate undershirts as a refinement practice for jacketed rhesus macaques (Macaca mulatta)

Jacketing of nonhuman primates (NHP) is a commonly used practice in the laboratory animal setting to support data collection with reduced direct human-to-animal interaction. NHP often wear jackets for several weeks, potentially leading to the formation of dermal lesions ranging from mild alopecia to severe full-thickness ulceration. We sought to evaluate the addition of a commercially available undershirt for primates as a possible refinement practice for our jacketed rhesus macaques. In this study, we compared the lesion count, location, and severity and differences in rectal body temperature between jacketed NHP with undershirts with those wearing the jackets alone. In both groups, most lesions (75%) were located at either the underarm or shoulder. The percentages of total lesions in the back and neck were lower in jacketed NHP that wore undershirts than in those that did not. In addition, the estimated odds of increased severity scores in jacketed NHP without undershirts was 1.80 times that for NHP that wore both jackets and undershirts. Both groups of NHP showed a significant decrease in dermal scores with time, indicating adaptation to the jackets with or without undershirts. However, there was no statistically significant decrease in lesion count, severity, or location in jacketed NHP that wore undershirts compared with those that did not.