Evaluation of hypochlorous acid as an ear flush in dogs with chronic otitis externa

BackgroundChronic otitis externa (OE) in dogs frequently requires anaesthetised ear flushing. ObjectivesTo evaluate hypochlorous acid as an ear flushing and antimicrobial agent in dogs with chronic OE. AnimalsTwenty dogs with chronic OE caused by the same organisms bilaterally. Materials and MethodsOne ear was flushed under anaesthesia with hypochlorous acid, the other with saline solution. Subsequently, the ear flushed with hypochlorous acid was cleaned with the same solution twice daily for 2 weeks, the other ear with a commercial ear cleaner. An ear medication containing miconazole, polymyxin B and prednisolone was used once daily in both ears. Clinical scores were determined before the flush. Ear cytological results were obtained, a hearing test was conducted before and after the ear flush, and a culture was taken directly after flushing. Ears were evaluated after 2 weeks of therapy. ResultsYeast was present in the ears of 11, cocci in one and a mixed infection in eight dogs. Five ears were negative on culture after flushing with hypochlorous acid, one after the saline flush. Clinical and cytological scores decreased significantly with both solutions after 2 weeks of treatment. There was no difference between treatments in any of the scores at any time point between treatments and in the results of the hearing test before and after the flushing procedure. Adverse effects were not seen. Conclusions and Clinical RelevanceHypochlorous acid is a suitable cleaning solution for canine OE.