Otitis externa (disease of the external ear canal) is one of the most common reasons that owners bring their pets to see the veterinarian. Some acute cases of otitis externa can be extremely painful for the pet. Chronic ear infections can not only be painful for the pet, but also frustrating for both the veterinarian and the owner.

What causes ear infections in pets?

Infections are caused by parasites (ear mites), bacteria, and/or yeast. The ear is a ‘natural incubator’, it is dark, warm and moist with very little air flow. While most infections involve the external ear canal, many also involve the internal ear canal and can be quite difficult to clear up.

Ear mites are tiny, microscopic, spider-like creatures that are invisible to the naked eye, but are recognizable by the brownish-black "coffee ground" discharge that they leave behind. This material is actually the dried blood and ear mite faeces produced from the numerous mites biting and sucking blood from your pet’s ears. Ear mites are transmissible to dogs, cats, ferrets and rabbits. When a single pet is found to have ear mites, ALL susceptible pets in the household need to be treated at the same time. Length of treatment can be prolonged and also depends upon the number of household pets.

Contrary to popular belief, most ear infections are not due to ear mites. Many ear infections are secondary to other problems such as allergies, skin conditions, trauma, tumours and foreign bodies. Ear conformation, the shape of the ear, also plays a big role in susceptibility to ear infection.

The earlier the infection is detected, the less pain and discomfort your pet will have to endure and the easier the problem will be to solve. If the ear infection is secondary to allergies, a quick fix does not exist and you are looking at long term ear maintenance for control. The two allergic diseases most commonly associated with otitis externa are inhalant allergic dermatitis and food allergic dermatitis.

What are the physical signs my pet might experience?

Your pet may show one or more of these physical signs when an ear infection is present:

a foul odour coming from the ear

frequent scratching at the ear

frequent head shaking

tenderness or irritability when the ear is touched

redness or inflammation in the ear

black, yellow, blood-tinged, or cream-colored discharge from the ear

How can I prevent ear infections in my pet?

Some ear infections are difficult to prevent. However, one way you can minimize them is to avoid prolonged wetness in your pet’s ears. If you give your pet a bath or allow your dog to swim, be sure to pat the insides of the ears dry with a towel so as not to allow bacteria or yeast to grow in the dampness; then apply a commercial ear cleaning product, such as Epiotic, that is safe and gentle on the ears. Some owners are able to use a combination of vinegar and alcohol to dry their pets ears. However, alcohol may be irritating to some pets. Commercial veterinary ear cleaning products (such as Epiotic) are both safe and gentle on the ears. We recommend that you use an ear cleaning product two to three times weekly to help with ear maintenance and cleaning. Besides drying the ear, these products also help to break up wax.

What type of pet is most susceptible to ear infections?

Ear infections are much more common in dogs than in cats. Ear infections may occur in any dog breed--Cocker Spaniels, Shar Peis, Poodles and other floppy eared dogs are the most susceptible. Cocker Spaniels are predisposed to ear infections because they have more secretory glands. Shar peis are predisposed because of conformation of their ear canal. Poodles are prone to ear infections because of excessive hair in the ear canal trapping moisture. Many pets with multiple allergies will sometimes have flare ups of eyes, ears and skin at the same time. Twenty-five percent of food allergic dogs have ear disease only as a clinical manifestation. Pets with floppy ears are more prone to ear infections because the air does not dry the ears naturally, as it does for pets with erect ears. Also, hair in the ear canals can keep the moisture trapped in the ear canal, which leads to infections. Hair in the ear canals should be removed regularly by your pet’s groomer or veterinarian.

How are ear infections treated?

Your veterinarian will do a comprehensive physical examination on your pet, looking not only at the ears but also the eyes and skin to assess for extended dermatologic disease. A cytologic examination will be performed to determine which infective organisms (bacteria and yeast) and inflammatory cells are present. Initial topical therapy will be based upon this test. In some cases a bacterial culture and antibiotic sensitivity testing may be needed. If the infection or inflammation is severe, your veterinarian may also prescribe oral antibiotics or anti-inflammatory agents.

For recurrent or chronic ear infections, diagnostics and treatment need to be aggressive early on. If the ear canal is too inflamed for complete visualization of the tympanic membrane, your pet may need to be on oral antibiotics and anti-inflammatory medication for two weeks prior to a follow up evaluation. If there has been no improvement in two weeks, then your pet is not a candidate for medical therapy and we recommend surgery for your pet’s ear problem.

Your pet may need to be sedated for initial or repeated deep cleaning of the ear canal and visualization of the tympanic membrane or to remove a tumour or foreign body. This will not only allow more effective treatment, but will also reduce the amount, and therefore the cost, of medication required. In chronic cases, a culture and sensitivity will need to be performed so that appropriate oral antibiotic therapy is chosen. Multiple cytologic and visual examinations will indicate how well the pet is responding to treatment.

Many ear infections are secondary to an underlying problem, such as allergies. In order to successfully control and prevent future ear infections, the underlying problem also needs to be addressed. This may involve other diagnostics, food trials, and DEFINITELY long term maintenance therapy.

Aggressive treatment for severe, chronic otitis is expensive and time consuming, but may avoid the need for surgery. This aggressive intervention will require several recheck examinations and long- term oral and topical therapy over a 2-3 month period of time. In addition, the ears will NEVER be completely normal and a lifelong preventive ear cleaning regimen is usually needed.

To administer liquid ear medication, squirt it directly into the pet’s ear inside the vertical ear canal. Massage the ear canal between your finger and thumb. You should hear a wet, squishy noise. If you do not, you may need to apply more medication or massage the ear canal more aggressively. For small dogs and cats, usually 3 to 4 drops suffice. For larger dogs apply 6 to 7 drops. Do NOT use cotton swabs as they push the wax further down and may puncture the ear drum. You can use small pieces of cotton or tissue to clean the external part of the ear. When using an ear flush, use copious amounts with gentle flushing and pressure. Too much pressure can easily rupture an unhealthy ear drum.

IF LEFT UNTREATED AN EAR INFECTION CAN CAUSE SO MUCH SCARRING THAT THE EAR CANAL BECOMES CLOSED. CHRONIC EAR INFECTIONS CAN ALSO CAUSE CLOSURE OF THE EAR CANAL. IN THESE SITUATIONS, YOUR PET WILL NEED SURGERY TO ALLEVIATE DISCOMFORT AND PAIN.

Also, if your pet is continuously scratching and shaking its head, he may suffer from broken blood vessels in the ear flap, a hematoma, which usually requires surgery.