Use of polyhexamethylene biguanide on wound healing in dogs

PURPOSE: To analyze the effects of polyhexamethylene biguanide (PHMB) on healing of clean surgical wounds in dogs. METHODS: Thirty healthy, non-neutered dogs of different breeds underwent elective ovariohysterectomy or orchiectomy, and a 1-cm circular abdominal wound was created. Animals were divided into three groups (n = 10). Groups T1 and T2 received PHMB dressings changed once and twice daily. The control group (C) had wounds cleaned daily with saline and covered with gauze. Macroscopic evaluations were performed daily for 10 days, assessing edema, exudate, cosmetic appearance, and color. After 10 days, excisional biopsies were collected for histopathology evaluating vascular proliferation, inflammatory cells, fibroblastic proliferation, collagenization, necrosis, hyperplasia, and reepithelialization, and immunohistochemistry for reepithelialization and angiogenesis. RESULTS: Macroscopic evaluations showed no significant differences among groups. Histopathology revealed greater collagenization in group C than in T2 (p < 0.05), while T1 did not differ from the others. Immunohistochemistry showed no differences in reepithelialization among groups. However, angiogenesis was higher in C and T2 than in T1 (p < 0.05). CONCLUSION: PHMB dressings neither demonstrate superior healing compared with gauze and saline cleaning nor impair healing and may represent an option for wound management in dogs.