The Effect of Different Preoperative Depilation Ways on the Healing of Wounded Skin in Mice

SIMPLE SUMMARY: An increasing number of animals, including pets, may undergo surgery due to diseases or cesarean section nowadays. To reduce surgical site infection, hair removal is a necessary step before the surgical procedure because of the dense hair layer on the skin. However, previous studies showed that inappropriate hair removal methods might even increase surgical site infection rates. Although there are many commonly used preoperative depilation methods, it still has no detailed, unified selection criteria for animal preoperative hair removal. Therefore, we intend to provide a scientific and practical reference for veterinarians. To explore more specific details on whether depilation affects the condition of a surgical site, we established a skin wound model after the depilation step and then compared four commonly used hair-removal methods through morphological assessment and histopathological analysis. Ultimately, we concluded that the electric shaving method is the best method for preoperative depilation, followed by the depilatory cream method, and the sodium sulfide aqueous solution depilation method is the worst. We hope that the results of this study can provide useful reference points for veterinarians and researchers and help refine surgical procedures and maintain animal welfare. ABSTRACT: Hair removal is necessary before operating on animals with dense hair layers. To provide an appropriate hair removal method and maintain animal welfare, we introduced four commonly used depilation methods—namely, scissors shearing, electric shaving, depilatory cream, and sodium sulfide, and made systematic comparisons, instead of only examining one or two methods, as reported in the past. To further assess convenience and possible effects on skin wound healing, we performed a skin trauma model after depilation in C57BL/6J mice and recorded wound healing time. Meanwhile, the skin tissues around the wound were stained with H&E and Masson. The results showed that the wound contraction rate of the sodium sulfide group was significantly lower than other groups at different points in time. Furthermore, depilatory cream and sodium sulfide methods could induce a topical inflammatory response on the third day after the operation and delay the regeneration of collagen fibers. We concluded that sodium sulfide depilatory has a significant negative effect on wound healing. Depilatory cream is gentler, with mild skin irritation and symptoms of inflammation. The electric shaving method is more convenient and safer, and thus could be the best choice for preoperative depilation.