Ear Conditions in Dogs and Cats

 

Ear infections are a very common disease of both dogs and cats. Infections can occur in the outer part of the ear canal (otitis externa), the middle ear (otitis media), or the inner ear (otitis interna).

External ear infections can be sudden or chronic. Both conditions cause alterations in the normal environment of the ear canal. The changes cause damage to the lining of the ear canal producing excessive wax, thickening of the lining of the ear canal, and scarring of the ear canal. As the condition becomes more chronic, the canal becomes reduced in size and becomes calcified. Once the ear canal is calcified, this condition may only be resolved by surgical intervention.

Ear infections of the middle ear are often an extension of the outer ear. The ear drum is usually ruptured at this time. Other causes of middle ear infections are polyps and cancer.

Signs of otitis externa are head shaking, redness of the ear, excess wax, malodor, itching, and pain and head tilt. Chronic outer ear infection results in rupture of the ear drum in approximately 70% of the cases involved.

Causes include ear mites , allergies, yeast infection, food allergies, foreign bodies such as plant awns (seen in the western part of the USA), obstruction due to cancer, polyps, and excessive hair. Autoimmune diseases can also cause ear infections.

Factors that perpetuate ear infections are bacterial infections, yeast infections, and fungal infections. Excessive moisture from swimming can also produce ear infections. There are certain breeds predisposed to ear infections. We also see topical drug reactions causing ear infections.

Diagnosis is made by examination, cytologies (microscopic exam of the ear samples), cultures, biopsies, and a thorough exam of the ear canal using magnificatin. (Vet Scope)

Cytology helps us determine the if infection is present, the type of bacteria or yeast and if the infection is due to mites. Cultures determine the specific antibiotic needed to treat the bacterial infection.

Treatment includes thorough ear cleansing, and appropriate antibiotics and ear cleaning by the owners. If food allergy is suspected a diet change may be recommended. Surgery may be considered if the ear is unresponsive to medical management. Surgical consideration may include changing of the drainage of the canal, removal of the entire ear canal, or removing polyps.

When the inner ear is infected, head tilt is a common sign. This type of infection may also affect nerves innervating the eye and face. When the eye is involved, size of the pupils of each eye may be different. Another eye dysfunction is loss of the ability of the eye to produce tears causing a painful eye problem of your pet. Other signs of otitis interna are head tilt and severe loss of balance.

Diagnostic tests of otitis interna include x-ray and MRI.

Otitis media must be treated aggressively by your veterinarian.