Diabetic wound healing is a major health problem encountered in both human and veterinary medicine. In this study, 30 Wistar albino rats were experimentally induced diabetes having bilateral full-thickness tissue loss and second-degree burns onto the skin and divided into three groups. The effects of a 14-day-wound treatment with NPH insulin cream (G1), ozonized cream (G2), and ozonized cream + NPH insulin cream (G3) was investigated. Photographic evidence of wound healing was measured on 3, 7 and 14 days. On the fourteenth day, the rats were euthanized, and scar tissue samples were collected for histopathological examination. It was observed that topical NPH insulin alone acted as a strong immunomodulator in preventing long-term inflammation that could lead to delayed wound healing. In G2 and G3 groups, the epithelization score was increased, additionally in G3 the fibroblast activation score was  increased as well. In conclusion, a combination of equal amounts of NPH insulin cream and ozonized cream contributed to wound healing by decreasing inflammation score and increasing epithelization and fibroblast activation.