Allergic skin disease 5: Ear disease

Bad ears, or otitis externa, is a common complaint of dogs with any form of skin disease. Those with food or air borne allergens are most frequently affected. Some mite infestations preferentially affect the ears also.

Due to the narrow nature of the ear canal, and the warm moist environment they represent secondary infections are common, and painful.

Yeast or bacterial infections are frequent problems. Primary disease is often caused by grass seeds entering the ear canal.

Dogs with hairy, or floppy ears, are more prone to problems eg. poodles and spaniel breeds.

What signs do I look for?

Ear infections are very painful, with the ear canals often very inflamed and sensitive. Dogs will regularly shake their head, and scratch their ears to try and remove debris. Affected dogs will often cry out when patted on the head. The ears themselves will often become very red, inflamed and develop an unpleasant odour. A discharge may also be seen which can be brown – yellow and dry or moist.

We need to look at the discharge under a microscope to determine the cause of the infection. If the infection is secondary to an allergy, the cause of the infection may not always be the same for your dog, so different treatments may be required each time problems occur.

Diagnosis

Most ear infections will not clear up without treatment. In chronic (long-term) infections the ear canal can become thickened and not allow the ear to drain. In severe cases infection will move through the ear drum, causing otitis media, which can lead to hearing loss.

Firstly we need to look down the ear canals to see what is going on. In some cases this is not possible due to your pets pain. In this situation we will either use anti-inflammatory medications for 7-10 days then reassess the ears, or check them under sedation.

In most cases a swab is taken for microscopic examination, and if necesary one is sent to the lab for bacterial culture.

It is imperative to eliminate the infection before we can adequately deal with the allergy issues. With the exception of foreign bodies (such as grass seeds) and certain types of mites, the vast majority of ear infections have an underlying allergic cause.

Treatment

Treatment of ear disease will often be done in two parts. Firstly eliminating infections, and secondly managing underlying disease.

The initial treatment may involve a combination of the following:

• Oral or injectable cortisone
• Ear drops
• Daily ear washes done at home
• Ear flush under anaesthesia
• Oral antibiotics
• Sedation or anaesthesia to remove foreign bodies
• Oral antifungal medications

Periodic ear swabs may be necessary to check on the progress of treatment.

The assessment and management of the underlying disease is the same as for other skin disease, and is covered in other data sheets in this series.