Surgical Management of Otitis Media in Dogs and Cats

It must be kept in mind that many differences exist in the origin/etiology of middle ear conditions of dogs and cats. The management of such conditions depends on the etiology and the surgical treatment is often different between both species. For dogs, otitis media is almost always secondary to primary external bacterial otitis (descending). The absence of tympanic perforation does not rule out otitis media. For cats, an ascending cause is responsible for the most cases of middle ear drainage obstruction, thus initiating a sterile inflammatory process. The scopes of this document are the most common middle ear surgical conditions in dogs (septic otitis media) and cats (polyps).

ANATOMICAL DIFFERENCES:

The main anatomic differences between dogs and cats middle ear include:

• The feline bulla tympanica has 2 cavities much more distinct than in dogs. One large and ventral (hypotympanum) cavity and another small craneal-ventral cavity (epitympanum and mesotympanum). Those cavities are separated by an incomplete bone septum medially.
• The inner bulla tympanica in cats is covered by epithelium that contains much more ciliated and secretor cells than in dogs.
• When approaching to the cat middle ear, the tympanic plexus distributes widely through the promontorium bone, but it is more exposed, probably more sensitive than in dogs and vulnerable to iatrogenic damage.  […]