Video otoscopy as a diagnostic tool for canine otoacariasis

Abstract

Canine otoacariasis, or otodectic mange, is a common parasitic disorder of dogs' ear canals caused by the mite Otodectes cynotis. Infestation can be detected through diverse protocols of varying sensitivity. We evaluated the use of video otoscopy in comparison with conventional otoscopy and cerumen examination under a microscope for diagnosing O. cynotis in dogs. Thirty-five dogs were evaluated bilaterally for the presence of ear mites, using a veterinary otoscope (Gowlands®), a video otoscope (Welch Allyn®) and the gold-standard technique of examination of swab-collected cerumen under a microscope. Each ear was considered to represent one sample, and 69 ears were examined, since one dog presented with one completely stenotic ear canal. Ear mites were diagnosed in 59.42% (41/69) through video otoscopy. The same 41 infested ear canals were detected by means of cerumen examination under a microscope, whereas conventional otoscopy was able to diagnose mites in only 39.13% (27/69). This difference was statistically significant (p < 0.001). Video otoscopy proved to be superior to conventional otoscopy, and equivalent to the gold standard for detection of O. cynotis in canine ear canals, and should be recommended for controlled trials on drug efficacy for treatment of canine otoacariasis.