Otitis Externa (Ear Infections) in Cats

Overview of Ear Infections in Cats

Otitis externa, commonly known as an ear infection, is characterized by inflammation of the soft tissue components of the external ear canal. It can affect cats but is more common in dogs. Ear infections can also target the middle or internal ear canal – for more information go to Otitis Interna in Cats

Below is an overview of ear infections in cats followed by in-depth information about the diagnosis and treatment of this condition.

Several factors may predispose your cat to ear infections, including:

• Abnormal ear conformation or anatomy such as nasopharyngeal polyps (more common in young cats)
• Water or hair in the ears
• Allergies
• Trauma
• Tumors (common in elderly cats)
• Foreign material in the ears
• Parasites
• Autoimmune disease
• Generalized skin disease

Infections are caused by fungus, bacteria or parasites. Laboratory tests can help to determine which of these is the cause in your pet. Ear mites (Otodectes) may cause approximately 50% of infections in young cats. Other common cause in cats are nasopharyngeal polyps in young or middle age cats and neoplasia (cancer) of the ear in senior cats.

What to Watch For

Common signs of ear infections may include:

• Scratching or rubbing the ears
• Head shaking
• An abnormal odor or discharge from the ear
• Pain when you manipulate the ear

Diagnosis of Otitis Externa in Cats

Veterinary care should include diagnostic tests to determine the underlying cause and help guide subsequent treatment recommendations. Tests may include:

• Complete medical history and physical examination with special attention to the ears and skin
• Cytology, which involves taking a sample of the ear discharge or any masses and examining it under a microscope. The discharge if evaluated for the presence of mites, yeast organisms or bacteria.

Some pets may require additional diagnostic tests to determine the underlying cause of the abnormalities. Pets with recurrent ear infections, those who respond poorly to treatment, pets with generalized skin abnormalities, or those with other health problems may need additional diagnostic tests. These may include:

• Culture and sensitivity involves taking a sample of the ear discharge and sending it to a laboratory to identify the specific bacteria present. The bacteria are exposed to multiple antibiotic samples to determine what will kill them most effectively.
• Radiographs (X-rays) may be recommended to determine the health of the ear canal and bone and to evaluate the extent of involvement. Some cases of otitis externa (inflammation of the OUTER ear) can progress to otitis media (inflammation of the inner ear).
• Complete blood count (CBC) and biochemical profile to check for factors that may contribute to the infection as well as to determine if a concurrent disease is present
• Allergy tests to determine if your pet is allergic to things that may irritate the ears, as well as the skin

Treatment of Otitis Externa in Cats

Treatments for otitis externa may include the following:

• Cleaning the ear. This can be accomplished by placing solutions in your pet’s ear at home or by having the ears cleaned by your veterinarian. Moderate to severe infections may require sedation and in-hospital flushing.
• Topical therapy. It usually consists of an ear medication that you place in your pet’s ear once or twice daily. The specific medicine and directions will depend on the cause of the infection. It is extremely important to follow your veterinarian’s directions carefully.
• Systemic therapy with glucocorticoids (steroids) to decrease pain and inflammation.
• Antibiotic therapy in cases of severe bacterial infection or ulceration
• Antifungal therapy in cases of severe or recurrent yeast infections
• Anti-allergy therapy

Home Care and Prevention

Optimal treatment requires a combination of home and professional veterinary care. Be sure to have your veterinarian or his/her staff show you how to place medication into your cat’s ears.

• Do not use cotton swabs in the ear; these may push infection and/or discharge deeper into the ear canal. Clean the ears before applying medication.
• Return to your veterinarian for follow-up examinations as suggested. Repeated cytology may be recommended to monitor therapy.

At home special care of your cat’s ears can help to maintain healthy ears. Dry the ears after bathing or swimming and check ears for foreign matter.

Also, at the first sign of scratching, head shaking, pain, swelling, odor, or discharge, have your cat’s ears checked by your veterinarian.

In-depth Information About Ear Infections in Cats

Other medical problems can lead to symptoms similar to those encountered in otitis externa. It is important to exclude these conditions before establishing a definite diagnosis. Examples are:

• Atopy is caused by an allergy. Cats with itchy skin disease caused by an allergy commonly have otitis externa.
• Autoimmune disease, such as systemic or discoid lupus erythematosus or pemphigus
• Contact allergy
• Food allergy
• Foreign bodies such as foxtail awns
• Ear disease like cancer, hyperplasia or polyps
• Parasites like ear mites, which are responsible for 50 percent of otitis in cats
• Polyps
• Seborrhea
• Trauma
• Tumors. The following have been reported: squamous cell carcinoma (more common in cats than dogs), histiocytomas, sebaceous gland adenomas, adenocarcinomas, basal cell tumors, mast cell tumors, chondromas, chondrosarcomas, trichoepitheliomas, apocrine gland adenomas, fibromas, fibrosarcomas, and papillomas.

In-depth information on the Diagnosis of Otitis Externa in Cats

Veterinary care should include diagnostic tests and subsequent treatment recommendations. Tests are needed to confirm the diagnosis of otitis externa and exclude other diseases that may cause similar symptoms.

The following diagnostic tests are often recommended:

• Complete medical history and physical examination to examine your pet’s external ears. Your veterinarian will pay close attention to the size of the ear canal, presence of pain, smell of ears, presence of hair or foreign material, masses or polyps, character of discharge/exudates, soundness of the ear drum, and general health. Your pet may need to be sedated.
• Cytology to identify parasites, yeast organisms, bacteria and cellular components. This test will help to determine the cause of otitis externa and choose the proper treatment for your pet.
• Culture and sensitivity tests in cases of recurrent infections, as there are some organisms that are often resistant to many antibiotics
• Biopsy of growths to determine the presence of tumors
• Radiography (X-rays) to evaluate the degree of the disease

Your veterinarian may suggest a referral to a dermatologist in difficult or recurrent cases or additional diagnostic tests to exclude or diagnose other conditions or to better understand the impact of otitis externa on your pet. These tests are selected on a case-by-case basis and may include:

• A complete blood count (CBC) to evaluate your pet for other problems such as infections or inflammations
• Serum biochemistry tests if there are other abnormal symptoms on the physical examination such as weight loss
• Urinalysis to evaluate the kidneys and bladder
• Thyroid level tests to determine the presence of hypothyroidism, which is the most common endocrine disorder that causes otitis externa in cats
• Adrenal function tests to rule out Cushing’s disease, which is hyperadrenocorticism secondary to excessive pituitary excretion of adrenocorticotropic hormone
• Allergy tests to rule out allergic disease
• Dietary trial to rule out allergic disease
• Fungal cultures in the presence of severe or recurrent fungal infections
• Skin scrapings to rule out mites such as Demodex

In-depth information on the Treatment of Otitis Externa in Cats

Treatment for otitis externa may include one or more of the following:

• Treatment of the primary disease process, the underlying factors that predispose your pet to infection, and the specific infectious agent. Flushing debris from the canal is critical prior to topical treatment. There are several types of ear cleaners. Ear cleansers can be detergent and ceruminolytic (products such as Epi-Otic, Oti-Clens, Routeen, Alo-Cetic) or antimicrobial (Chlorhexiderm, Malaseb). Ear cleaning should be once or twice daily until all debris is removed which is typically 3 to 7 days. Excessive cleaning should be avoided is it can cause ear problems. Cleaners can keep the ear moist and susceptible to infection.
• Initial management includes cleaning your cat’s ear. This can be accomplished by placing solutions in your pet’s ear at home or by having them cleaned by your veterinarian. Moderate to severe infections may require sedation and in-hospital flushing. Uncomplicated ear infections respond well to topical ear medications such as Antimax, Otomax, Surolan.
• Topical therapy usually consists of ear medication that you place in your pet’s ear one to two times daily. The specific medicine will depend on the cause of the infection. It is extremely important to follow your veterinarian’s directions on getting the medicine in your pet’s ear. Improper medication and improper administration is a common cause for treatment failure.
• Systemic therapy with glucocorticoids, such a prednisone, may be given to decrease pain and inflammation. These are hormones often used as inflammatory agents. It is often used for 10 to 14 days when pain and inflammation is present. Topical glucocorticoids can also be used.
• Antibiotic therapy may be indicted with severe bacterial infections or ulceration. Antibiotics may be chosen based on cytology and/or bacterial culture.
• Antifungal therapy is indicated in cases of severe recurrent yeast infections.
• Regular follow-up visits to your veterinarian are important to ensure that your cat’s condition does not worsen.

Home Care for Cats with Otitis Externa

Optimal treatment for your cat requires a combination of home and professional veterinary care. Follow-up can be critical. Follow-up for otitis externa often includes the following recommendations:

• Administer prescribed medications as directed and be certain to contact your veterinarian if you are experiencing problems treating your cat.
• Long term maintenance cleaning may be recommended in cases of long-standing infection. Cleaning procedure can be daily or weekly depending on the rate of wax and debris formation.
• Administer any prescribed medications. NOTE: Inability to medicate your pet is a common reason for treatment failure.
• Schedule regular veterinary visits to monitor your pet’s condition. Repeat cytology examinations is critical to curing long time treatments.
• Periodic ear evaluations with cytology may be recommended.
• Ear cultures may be useful in long-standing infections.
• Of course, the precise follow-up depends on the severity of your pet’s disease, response to therapy and your veterinarian’s recommendations.