Disease of the ear canal (canker) is one of the commonest diseases of dogs affecting one in five pets at any one time. It is commonly thought that ear problems may be inevitable in some breeds, such as some spaniels. However, this is far from the case and failure to tackle inflamed ear canals will result in chronic pain, inflammation and infection. In time untreatable chronic end-stage ear disease develops.

SO WHAT CAUSES EAR CANKER?

By far the commonest cause of ear disease is skin allergy. Over 90% of dogs with chronic or recurrent ear disease will have a skin allergy of some sort. Atopy (allergic inhalant dermatitis) is the single most common cause of ear disease in the dog. However, the ear canal commonly becomes hot and inflamed as a result of flea bite dermatitis and in cases of mange. Food allergy is a common cause of ear disease in dogs under one year of age.

Foreign bodies, such as grass seeds, can cause ear disease as can impacted wax or hair. Ear mites are an occasional cause of uncomplicated ear disease in young dogs. Ear mite infestation is not found in chronic ear diseases. Hormonal imbalance as a result of thyroid or adrenal gland problems causes excessive secretion of ear wax. This often causes the ear canals to become under-ventilated and infected.

Elderly dogs and cats often develop polyps and tumours of the ear canal lining. This is a frequent cause of chronic, smelly ear infections. Malignancies of the ear canal are not infrequent occurrences.

Lastly, about 70% of dogs with chronic canker will have extension of infection into the middle ear. Ear drops are ineffective at treating pets with concurrent middle ear infections.

FACTORS MAKING EAR DISEASE WORSE

Dogs with long pendulous ears such as Bassets and Spaniels, with hairy ear canals (Poodles) or narrow ear canals (Shar Pei) often suffer more troublesome ear infections.

Swimming and excess moisture soften the ear canal lining and makes the ear susceptible to excess waxing and yeast infections. Allergic ear disease is commonly complicated by bacterial or yeast infections that can be difficult to treat. With persistent inflammation the ear canal lining becomes thickened and the ear closes up. This further interferes with the normal ventilation and cleaning of the ear canal.

In all cases of ear disease, it is necessary to establish the cause of the problem and to eliminate factors that may perpetuate the disease.

TREATMENT OF ACUTE EAR DISEASE

We recommend anti-inflammatory/antibiotic ear drops daily for a minimum of 14 days. We will also prescribe a short course of steroid tablets for 1-2 weeks to reduce inflammation and assist ear cleaning. Enough ear drops should be placed in the canal for the ear to make squidgeing sounds when massaged. This may require more drops than the manufacturer’s recommendations. Large dogs may require considerably more ear drops than small breeds. Your pet will be re-evaluated at the end of the two week treatment period. If a foreign body is suspected, we will need to inspect the ear canal under general anaesthesia. If ear mites are suspected, your pet will need treatment with an insecticide such as Frontline or Stronghold.

HOME CARE: After acute inflammation, the ear canal will produce excessive wax for several weeks. Cleaning with proprietary ear cleaners, such as Leo Ear Cleaner or Epi-Otic, is required every second day for several weeks followed by twice weekly cleaning for a minimum of 6 weeks. Thereafter, the ears should be cleaned weekly. Ongoing treatment may be required for underlying allergies.

TREATMENT OF CHRONIC EAR DISEASE

Chronic ear disease can be difficult to cure. We commonly  X-ray the middle ear cavities, take blood tests if hormone disorders are suspected, examine the ear canal and ear drum with an endoscope, flush the ear to remove all debris under general anaesthesia  and take ear and skin swabs +/- skin biopsies

Infections are commonly found that are resistant to antibiotics. We sometimes have to compound our own treatments to tackle such infections as the choice of antibiotics in the standard ear treatments is very limited. Repeated flushing and cleaning under general anaesthesia may be required at two weekly intervals. Unfortunately, flushing infected ears cannot be done under sedation – it is too painful for the dog. Since chronic ear disease can be very uncomfortable for your pet, we normally re-check cases of chronic ear disease every two weeks until the ears are comfortable. In cases of suspect food allergy, we recommend feeding a proprietary “exclusion” diet, such as Eukanuba Dermatosis Formula for a minimum of 6 weeks.

MIDDLE EAR DISEASE

70% of dogs with chronic ear disease will have involvement of the middle ear. These cases respond very poorly to medical therapy. However, repeated flushing under general anaesthesia may result in clinical cures. Unfortunately, for the majority of dogs, surgery is required to treat middle ear disease. Surgery drains infection from the middle ear cavity (bulla osteotomy) and removes the diseased ear canal. Although surgery for middle ear disease is technically difficult and does result in total hearing loss on the affected side it does provide a cure for persistent ear disease in all cases