Otic is an adjective meaning of or pertaining to the ear. In equine veterinary medicine the term appears in compound clinical descriptors such as otic discharge, otic examination, and otic medications. Horses possess highly mobile external ear pinnae controlled by sixteen muscles, enabling approximately 180 degrees of rotation, which allows precise sound localization and serves as a behavioral communication signal. The equine ear is divided into the outer ear (pinna and external auditory canal), the middle ear (tympanic membrane, ossicles, and tympanic cavity), and the inner ear (cochlea and vestibular apparatus). Otic disease in horses is less common than in small animals but includes otitis externa caused by bacterial or yeast overgrowth, aural plaques (papillomatous lesions caused by papillomavirus), and tick infestation within the ear canal. Guttural pouch disorders, though involving structures adjacent to the middle ear, can produce signs resembling otic disease including head-shaking and unilateral discharge. Otic examination requires appropriate restraint and a good light source; a video otoscope improves visualization of the tympanic membrane and deep canal. See also ear canal parasites as a common cause of otic irritation, and mucous membrane assessment for reading discharge and tissue health during examination.
Further Reading
- ear anatomy (Wikipedia)
- For veterinary detail on equine ear anatomy and common otic conditions: ear structure and function in horses — MSD Veterinary Manual