Otitis Externa

Otitis externa is an inflammation or infection of the outer (external) ear canal. Many factors can cause or contribute to the development of otitis externa in dogs and cats. Parasites (e.g., ear mites, ticks), foreign bodies (e.g., grass awns, dried medication, dried wax, displaced hair), allergic disease (canine atopic dermatitis, food allergy), and diseased causing abnormal skin renewal time (keratinization disorders) have all been implicated as factors that can cause otitis externa. Factors that predispose and animal to develop otitis externa include ear structure (e.g., long floppy ears, heavily haired ears, long narrow ear canals (growths, swelling of the ear canal tissue). Factors that usually cannot cause otitis externa by themselves but can be a significant problem in need of treatment are bacterial and yeast ear infections. Sometimes, in long standing cases of otitis externa, problems can be seen in the ear past the eardrum (middle ear-otitis media), and these problems also need to be treated. It is most important to recognize that many factors may come together in development of your pet's ear problem. Recognition and subsequent treatment of all factors are the keys to successful clinical management of the otitis externa. A variety of tests may need to be performed, including examination of the discharge from your pet's ear under a microscope, bacterial culture of the discharge from your pet's ear, blood testing or skin testing for allergy, a dietary change to determine whether a food allergy is the cause of your pet's ear disease, and x-rays of the skull to aid in diagnosing middle ear problems. One or more in-hospital ear cleaning procedures may need to be performed on your pet. This may be as simple as ear cleaning requiring just a few minutes with no or minimal sedation to more involved ear cleaning requiring more time and general anesthesia. The goal of complete resolution of your pet's ear disease depends heavily on your ability to clean and medicate your pet's ears, follow through with therapy based on the results of the various tests, and faithfully return your pet for serial reevaluations at your veterinarian's clinic. Recurrent otitis externa that is not managed properly can cause chronic irreversible changes in the ear canal, most notably a narrowing of the ear canal diameter. This narrowing does not allow medication or ear cleaning solution into the affected area and also does not allow the normal earwax secretions to exit from the ear canal. Even though your pet's ear may seem to be improved (less discharge, less smell, less discomfort,) the ear disease may not be completely resolved and premature discontinuation of therapy can be detrimental to the chances of final resolution of the ear problem. Sometimes, the underlying problem cannot be found or corrected. In these cases, a maintenance cleaning and medicating protocol may need to be formulated for your pet. If this protocol is followed, many cases of ear disease can be controlled with minimal time and effort on your part and minimal discomfort for your pet. Appropriate cleaning is a vital part of the overall program for appropriately addressing ear disease. The ear canal should be thoroughly cleaned of all debris before any medication is instilled in the canal. Your pet may object to having its ears cleaned initially, but better acceptance is usually seen with time. If your pet's ear canal is red and uncomfortable at the beginning of treatment, gentle but thorough cleaning helps. After filling the ear canal with the ear cleaning solution, massage of the canal helps loosen the debris and discharge. The debris can then be massaged up from the base of skull (where the ear meets the head) to a cotton ball that is seated firmly in the opening of the canal. This procedure should be repeated until debris is no longer recovered on the cotton ball. Medication is then placed in the canal and massaged down to the base of the ear. Q-tips should never be used to clean the ear, except on the outer ear folds. The key to successful cleaning is being consistent and thorough. Reevaluation at the clinic is also a vital part of successful clinical management. Your pet's ears may appear normal to you but may need continued medication and cleaning for complete resolution of the inflammation or infection. In addition, especially in chronic cases of otitis externa, a maintenance cleaning or medication protocol may need to be formulated on the basis of the information obtained from the reevaluation visits. The above is general veterinary information. Do not begin any course of treatment without consulting your regular veterinarian. All animals should be examined at least once every 12 months.