Tufts University School of Veterinary Medicine, Dermatology Service, Walpole, MA, USA; Bizvet, Inc., Westborough, MA, USA
©2005 Lowell Ackerman D.V.M. No portion of this material may be reproduced without the written consent of author.
Introduction
There are few things as frustrating as dealing with a dog with chronically inflamed ears. They're swollen, they're painful, and owner and pet are just looking for some long-term relief. That shouldn't be to tough, but despite a plethora of ointments, drops, and flushes available, and the most expensive antibiotics money can buy (often several of them in succession), managing these cases can be a nightmare.
Importantly, antibiotics are not the sole answer. In the vast majority of cases, bacteria are not the primary problem and, more specifically, the bacteria cultured from the outer ear are probably not the ones secondarily involved in most chronic cases. Undiagnosed rupture of the eardrum is the number one cause of chronic otitis externa. Even when the eardrum has healed over, most of the bacteria responsible for keeping the problem ongoing originate from the middle ear and, in roughly 85% of cases, these are not the same bacterial species isolated from swabs of the external ear canal.
Causes
There are lots of different causes for otitis and, while it may seem surprising, true bacterial causes are actually rare. While bacteria and yeast are frequent complicating factors for ear problems, the most common underlying causes are inhalant allergies, adverse food reactions, metabolic problems, and immune-mediated conditions. Only when the correct underlying cause has been identified and managed will the condition be readily controlled.
Antibiotics can act as a Band-Aid for the problem, but in the vast majority of cases they provide only temporary relief. Once they are discontinued, if the underlying problem has not been corrected, the ear problem is likely to recur.
Management
There are many ear drops, creams, ointments, and even powders that are sold for ear problems, and yet some of the simplest remedies are the most satisfying if the underlying problems have been addressed. Many of the ingredients in ear medications can cause side effects, and most are not meant to be used in cases where the eardrum has been damaged. In fact, many of the antibiotics and antiseptics in ear medicines can cause deafness if the eardrum is ruptured and they enter the middle ear. Many of the corticosteroids in the most common ear medicines are potent and not meant to be used for more than about 7 days, or they get absorbed into the bloodstream. So, treatment of ear problems can be very rewarding, but shortcuts rarely result in a satisfactory outcome. When the underlying problem has been identified and corrected, treatment is successful in the vast majority of cases.