Effect of topical ozonated sunflower oil on second intention wound healing in turtles: a randomised experimental study

Background: Ozone is an antimicrobial agent that in experimental and case-control studies has been found to exert a positive effect on wound healing. Wild and pet chelonians frequently present insidious wounds exhibiting secondary infections and/or delayed healing. Objectives: Evaluate the effects of topical ozonated sunflower oil on second-intention healing of acute experimental skin wounds in red-eared sliders (Trachemys scripta elegans). Methods: Randomised within-subject controlled study; Group 1 (n = 24) was used to assess clinical healing features; Group 2 (n = 12) was used for histological evaluation in which two sets of wounds were biopsied at 2, 7, 14, 21, 28 and 42 days over the course of the cicatrisation process. A single 6 mm diameter wound was made on each rear limb and topical ozonated (950 peroxide value) and non-ozonated sunflower oil were applied daily for one week on treated and contralateral control wounds, respectively. Results: Mean wound size was significantly lower in the ozone-treated group at day 28 (p < 0.0001) with differences of clinical relevance (74.04% vs. 93.05% reduction of initial wound size). Histologically, the acute inflammatory reaction was enhanced in treated wounds, with significantly higher numbers of heterophils (p = 0.0016), lymphocytes (p < 0.001) and fibroblasts (p < 0.001). Conclusions: Daily topical application of ozonated sunflower oil over the course of one week improved the healing of acute, full-thickness skin wounds in chelonians. This clinical outcome was histologically correlated with an enhanced acute inflammatory reaction, as well as the production and remodelling of collagen fibres.