Comparison of 3 Topical Treatments against Ulcerative Dermatitis in Mice with a C57BL/6 Background

Ulcerative dermatitis (UD) is a common condition in C57BL/6 mice and strains with this background. The etiology of UD is unclear but appears to have a genetic component associated with the C57BL/6 strain and has been reported as secondary to a variety of conditions. Treatment is unrewarding, resulting in euthanasia in many cases. In the present study we compared 3 topical treatments against spontaneous UD in mice with a C57BL/6 background. In total, 301 mice of both sexes were included in this study, and the tested treatments comprised bacitracin-neomycin sulfate-polymixin B sulfate ointment twice daily, 10% povidone-iodine ointment plus 1% silver sulfadiazine cream once daily, and 0.005% sodium hypochlorite once daily. Lesion healing was defined as complete skin reepithelialization with or without hair regrowth. Sex, age, lesion location, and type and length of treatment were analyzed by using univariate and multivariate logistic regression. Of the 79 mice treated with triple-antibiotic ointment, 27 (34%) healed, compared with 43 of the 125 (34%) treated with povidone-iodine and sulfadiazine and 69 of the 97 (71%) treated with hypochlorite. Lesion size and treatment with 0.005% sodium hypochlorite were the only significant predictors of healing; all other variables were not statistically significant in multivariate analysis. We conclude that 0.005% sodium hypochlorite is an effective topical treatment alternative for UD in C57BL/6 mice and strains on this background, and a favorable prognosis depends on the early identification and treatment of those lesions.