Dermatophytosis is a mycotic disease of the skin that is resistant to treatment. The aim of this study was to investigate the treatment efficacy of a novel antimicrobial agent, Hypochlorous Acid (HOCL), on dermatophytosis of cats and dogs, in comparison with Ketaconazole. In this study, a total of 76 animals (26 cats and 50 dogs) without any disease other than skin fungal infection after clinical, hematological, biochemical, microscopic and Wood's lamp examinations were used. Subjects were randomly assigned to two equal treatment groups within their own species as HOCL: HP and Ketaconazole: KT. Naked eye inspection results were collected on the 8th, 11th and 15th days of all patients. The study was terminated on the 15th day by collecting the Wood's lamp and microscopic examination data together with the last inspection finding. Findings were analyzed statistically with chi-square and CART (Classification and Regression Tree) algorithm test. Inspection results of the treatment groups exhibited significant recovery over time (day 8, 11 and 15) for both species (p0.05). According to the microscopic examination results, a significant statistical difference was observed between the HP and KT groups (p0.05). As a result, it was concluded that HOCl has an effect on dermatophytosis of cat and dogs, although not as much as Ketaconazole, but further studies are needed to reveal the results more clearly.