Ear Mites in Cats and Dogs ~ Pawprints and Purrs, Inc.

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Ear Mites in Cats and Dogs

What are ear mites?

While there are several types of mites which may infect cats and dogs, Otodectes cynotis is the mite most commonly seen. Ear mites are a external parasite which causes significant discomfort. Ear mites can live on any part of the body, although they generally live in the ears. They are the most common cause of otitis externa (inflammation of the outer ear canal) in the animals. They are most often seen in kittens and puppies, but they can affect cats and dogs of any age and are extremely contagious.

The mites feed on tissue debris and secretions from the ear canal lining. With repeated irritation, the ear canal thickens and debris builds up within the ear canal. This debris, caused by mite waste products, dead tissue and fluid resembles coffee grounds. In chronic (long term) cases of ear mites in cats and dogs, there often is secondary bacterial and yeast infections present that complicate the treatment and create even more stress on the animal.

What are the symptoms of ear mite infestation in cats and dogs?

Head shaking
Scratching the ears (there may be sores around the ears as a result of scratching)
Reddish-brown to black discharge (crusts and cerumen) in the ears that resemble coffee grounds
Odor
Sometimes there seem to be no observable signs of ear mites

In chronic (long term) cases of ear mites in cats and dogs, there often is secondary bacterial and yeast infections present that complicate the treatment and create even more stress on the animal. Damage to the ear could include a thickening of the skin or infection which is caused by the cat or dog damaging the skin by scratching, and bacteria entering these wounds.

What is the life cycle of ear mites?

The ear mite life cycle, which takes about twenty-one days from egg to adult, entails going through four different stages:

Stage 1: The Eggs
Female ear mites usually lay about 5 eggs daily during their entire adult life. Deposited on the surface lining of the ear canal, the eggs hatch within 4 days.
Stage 2: The Larvae
Once hatched from the eggs, the larvae feed for 4 days then rest for 24 hours as they molt into the nymphal phase.
Stage 3: The Nymphs
Two stages of nymphs are recognized. Each feeds for 3 to 5 days and then rests and then molts to the next stage.
Stage 4: The Adults
Just barely visible to the naked eye, the adult ear mite appears white in color and feeds off the epithelial debris in the animal's ear. There can be literally thousands of mites crawling about the ear canal and external ear surfaces. Ear mites do not burrow into the skin as Sarcoptic Mites and Demodex Mites do. They are communicable from one animal to another by direct contact.

How are ear mites diagnosed?

A diagnosis of ear mites by the veterinarian is usually made by one of the following methods:

Direct visualization of the mites with an otoscope
Microscopic examination of the ear discharge

What are the treatments for ear mites?

Although some cats and dogs show no outward signs of ear mite infestations, the mites can be diagnosed as described above. In most cats and dogs with ear mites, if you briskly rub the ear canal area the animal will respond by automatic scratching movements of the back leg. Triggering this automatic scratching movement seldom occurs in animals that do not have ear mites. Veterinarians check for ear mites as part of the routine physical exam, especially in multi-pet households.

There are a number of medications used to treat ear mites in cats and dogs. Your veterinarian will prescribe an effective product. One study showed that treatment with ACAREXX^TM (ivermectin) was 92% effective in treating adult ear mite (Otodectes cynotis) infestations after 7 days. In a well-controlled clinical field trial, one treatment of ACAREXX^TM was 94% effective in clearing cats/kittens and dogs/puppies of adult ear mite infestations within 7 to 10 days. The veterinarian may prescribe a different method or different medication such as Tresaderm® liquid; be sure to have a follow-up exam done four weeks after prescribed treatment.

Can I catch ear mites from my cat or dog?

These mites can, but seldom do, infest humans.

Page URL: http://www.sniksnak.com/doghealth/earmites.html

Resource References:
Much, much appreciation to Dr. Raymond Van Lienden, DVM of Clifton, VA USA for his extensive research in locating the material found on this page. Thank you, dear Doctor!