Stenotic Ear Canals

A common finding in dogs with otitis externa is a narrowed ear canal. Within the tube of skin that makes up the external ear canal, any swelling translates to decreased lumen diameter. When the lumen of the ear canal becomes narrowed or occluded, stenosis results (Figure 7-2). The stenosis magnifies the severity of the ear disease, making examination and treatment of the otitis externa more difficult.

A brief review of the anatomy of the external ear canal is helpful in delineating the mechanisms involved in creating the stenotic ear canal. The ear canal of the dog is lined by keratinizing stratified squamous epithelium.