By: Don Coats, DVM
Centreville Veterinary Hospital

This article will strive to give the reader some background and insights into ear diseases in dogs. I will describe some home care procedure, anatomy and explain predisposing factors to disease; pointing out that many cases of ear disease have causes elsewhere in the body and that some medications used in the wrong manner can actually cause ear disease.

Figure (1) should help pet owners understand the anatomy of the ear canal and help explain that a delicate microenvironment exists inside. This area is normally maintained by the motility of the lining cells, humidity, and pH keeping the living forces in balance and self regulated. This principle is obvious in most of our pets. Even in some Poodles, Schnauzers, and others with “natural” hair in their ears, if you see only a little brown and a little wax and it doesn’t smell rancid or look irritated, you should not clean them at all. Obviously, ask your veterinarian if you are unsure if it needs attention.

Special consideration applies to breeds like the Bassett, Spaniel and others. When cleaning is required as maintenance, it is important to know that you should be gentle, yet thorough, leaving the ear clean and dry. In my opinion, a common mistake made in home care is not being thorough enough in the mechanical part of cleaning. To clean the horizontal canal effectively, without causing added trauma, extra time is required – slowly massaging the base of the ear while a cleaning solution is in place. This creates a little turbulence at a level where cotton tip applicators should never go. The cycle of repeating these steps two or three times and permitting the dog to shake its head between soakings, and then conclude with careful blotting of the accessible upper part should be the standard. Medications should be applied only if a diagnosis has been made and a treatment
plan described.

Figure 1

Cross section model of the dog’s ear:
A) unaided visibility of the top of the vertical canal.
B) bottom of vertical canal, angle that complicates visualizing.
C) end of horizontal canal- problems often occur between B and C.

Examination of the ear is more difficult for veterinarians than human doctors in that dog and cat ear canals are longer and more tortuous. Because it is L shaped, it is awkward for the examiner to view the full length of the canal without causing discomfort to the dog.

At Centreville Veterinary Hospital, we use a specially designed video scope which aids not only in optimal examination but also permits photo records, accesses debris removal, and provides deep, gentle flushing (under brief anesthesia). Our staff makes an extra effort to educate and assist clients in effective home care.

Digital photo of a wax plug lodged deeply inside the horizontal canal of a dog. This rather common problem can be readily corrected using the video otoscope.

Ear diseases have primary causes and, often, a secondary cause as well as perpetuating factors. A small percentage of primary causes are “superficial”, parasites or foreign material, and are easily correctable. Unfortunately, most of the serious and chronic cases have a primary cause other than in the ear—such as allergy, low thyroid function, food sensitivity or nutritional factors. Perpetuating factors such as bacteria or yeast infection and scar tissue sustain the disease process. Relapsed episodes through time (common in the Cocker Spaniel) can create a situation where surgery is the only alternative in order to provide reasonable relief of suffering.

In conclusion, I would advise pet owners to respect the advice for recheck exams and follow the treatment schedule carefully. It is sometimes tempting to home diagnose and use previously dispensed topical ointments inappropriately. Repetition of inappropriate home diagnosis and treatment can sometimes create a contact allergy reacting to the medication or in other ways disable the natural healing ability in the ear.

Dr. Coats has been in small animal practice for over 30 years at Centreville Veterinary Hospital where he has had a special interest in reconstructive surgery. He enjoys his own adopted pet cluster of two terriers and three cats, but in past years, he has taken great pleasure in sled dog racing and his several Border Collie running buddies. His recreation activities include running, backpacking, and photographing with a devotion to natural history.

ANIMAL HOSPITAL
3705 Lancaster Pike
Wilmington, Delaware 19805
(302) 998-2995
24 Hour Emergency
www.windcrestanimal.com

TALLEYVILLE VETERINARY HOSPITAL
3001 Concord Pike
Wilmington, Delaware 19803
(302) 478-0648
www.talleyvilleveterinary.com

HOCKESSIN ANIMAL HOSPITAL
643 Yorklyn Road
Hockessin, Delaware 19707
(302) 239-9464
www.hockessinanimal.com
Centerville Veterinary Hospital
302-655-3315
5804 Kennett Pike, Wilmington, DE
(next to Buckley’s Tavern)
www.centrevilleveterinary.com