Montgomery Pet Skin and Ear Clinic

Louis N. Gotthelf, DVM
Member of the American Academy of Veterinary Dermatology

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EAR DISEASES IN DOGS
AND CATS

Dr. Louis N. Gotthelf
Member of the American Academy of Veterinary Dermatology

Author of Small Animal Ear Diseases; An Illustrated Guide, 2nd ed.

Our Video Otoscope allows a high magnification detailed examination of the ears

Dogs and cats get ear disease very often, but they are completely different in their causes and treatments.

DOG EAR DISEASE

Although both dogs and cats get ear mites, mites are actually a very rare cause of ear disease in dogs. It is pretty common in cats, though. We see many patients whose owners go to the store and get an ear mite treatment to use before coming to the veterinarian. This can actually be dangerous if there is a ruptured eardrum or any ulcers in the ear canal.

Dogs with ear disease often have smelly ears, they scratch or rub them a lot, or they may even develop an aural hematoma, a pocket of blood between the skin and the ear cartilage. The ears will be red and scaly or they may have a liquid discharge coming out of them. Ear infections are painful, so when you try and pet the dog, he may snap at you from the pain.

In dogs, ear disease is almost always secondary to some type of allergy. It could be a food allergy or it could be an allergy called atopic dermatitis from pollens, molds, or housedust mites. Sometimes a contact allergy results from something in the environment or medicines that the ears are sensitive to.

For whatever reason, the skin of the dog’s ear becomes inflamed and itchy followed by wax production from the glands that line the ear canal. Bacteria and yeasts, normally found on the skin in small numbers, begin to grow on this material, resulting in more skin irritation. If the dog gets the ears wet from swimming or bathing, then they are seeded with other types of bacteria that will also grow in this dark, warm, moist environment.

Because of the chronic inflammation of the ears over a long time, there will be physical changes to the normally smooth ear canal lining. Roughened areas may develop, the skin may develop ulcers because of some of the bacteria, there may be swelling and closure of the ear canal, or there may be scar tissue that has formed partially or completely closing off the ear canal.

Dogs that have ear infections year after year may also have a ruptured eardrum that results in an infection occurring in the middle ear or inner ear. This is a more serious type of infection and requires very special treatment to help to resolve.

Treatment of ear disease is dependent on the type of problem found in the ear on examination. To properly examine an inflamed, infected ear, we will use a short acting anesthetic and examine the painful ears with our video otoscope.

We also take swabs of the material in the ears and we look at this stained material under the microscope to determine the type of infection present, if any. We also sometimes will do a bacterial culture to help us identify and treat certain bacterial infections that are not responding to therapy with antibiotics.

Many other ear conditions can be identified by our video otoscope. They include tumors of the ear canal, cysts that may form on the ear canal skin, polyps from the middle ear, foreign material like plant parts or bugs becoming lodged in the ear canal, and wax and hair impactions at the eardrum, very common when Q-tips are used by owners.

In most cases, the entire ear canal will be flushed out in order to expose the affected ear canal skin. Medication can then be put on this skin rather than putting it on top of the waxy debris filling the ear canal. Ear treatment is tailored to each individual patient based on a number of factors.

We will also try and determine the underlying allergic cause of the ear disease so that we can help to prevent painful ear infections in the future.

CAT EAR DISEASE

Cats with itchy ears often have ear mites. These bugs colonize the cat’s ear canal and they set up nests in the ear wax. With our video otoscope, we can easily see the hoards of mites crawling around in the ears. Ear mites have mouthparts that are of the chewing type and they can chew off the lining of the ear canal resulting in some blood drying up in the ear canal and they can chew off the top layers of the eardrum, which are responsible for sliding across the eardrum, cleaning it from accumulation of debris. This results in the formation of a wax plug attached to the eardrum that needs to be removed periodically.

To treat ear mites, we first clean out all of the dark dried waxy material that holds the ear mites and their eggs. We then apply a topical insecticide into the ear canals to kill any remaining mites. Because cats scratch their ears with their rear feet, mites can get onto the feet and must crawl all the way to the ear to reproduce. They bite along the way and can cause skin rashes. In addition, cats sleep with their ear nuzzled into their flank and the mites can get on the skin that way also. So we give a whole body treatment injection to prevent re-occurrence of the mites.

Ear mites are highly contagious from cat to cat and any in-contact cats should also be checked and treated.

Unlike dogs, cats rarely get bacterial or yeasty ear infections. They also show allergies differently than dogs.

Cats get middle ear infections in the same manner as children do. Bacteria from the throat and nose area migrate up the eustacian tube into the middle ear when the cat sneezes. That seeds the middle ear with bacteria and that results in inflammation and infection of the middle ear cavity. This is very painful and it requires us to rupture the eardrum to relieve the pressure that builds up. Some cats develop polyps in their middle ear as a result of severe inflammation. A polyp is a non-tumorous growth of scar tissue. Polyps can grow large within the middle ear and they often grow right through the eardrum and end up growing into the external ear canal. Cats with polyps have a fleshy mass in their ear with large amounts of mucus and pus in the external ear. Surgery is the treatment for removal of polyps.

Should you suspect that your dog or cat has something wrong with the ear, please let us examine the ears with our video otoscope with you present so we both can see what is going on in the ears. Call our office at 272-2200 and schedule an appointment