Ear Mites (Otodectes) in Cats

What are ear mites?

The ear mite Otodectes cynotis is a surface mite that lives on cats, dogs, rabbits and ferrets. It is usually found in the ear canal but it can also live on the skin surface. The entire ear mite life cycle takes place on animals. Ear mites are highly contagious, and cats become infested by direct contact with another infested animal. The mite is barely visible to the naked eye and may be seen as a white speck moving against a dark background.

What is the life cycle of the ear mite?

It takes approximately 3 weeks for a mite to develop from egg to adult, going through a total of 5 stages. Adult ear mites live about 2 months, during which time they continually reproduce. The entire ear mite life cycle takes place on the host animal, although mites can survive for a limited time in the environment.

What are the clinical signs of ear mites?

Ear mites are the most common cause of feline ear disease and infection. They are the second most common ectoparasite (external parasite) found on cats; the most common is the flea. Infestations are most common in kittens and young cats although cats of any age can be affected. Clinical signs of infestation vary in severity from one cat to another and include combinations of:

1.  Ear irritation causing scratching at the ears or head shaking

2.  A dark waxy or crusty discharge from the ear

3.  Areas of hair loss resulting from self-trauma - scratching or excessive grooming

4.  A crusted rash around or in the ear

5.  An aural hematoma - a large blood blister on the ear, caused by rupture of small blood vessels between the skin and cartilage - caused by scratching at the ears

Skin lesions most frequently affect the ear and surrounding skin but occasionally other areas of the body may be affected.

How are ear mite infestations diagnosed?

Typical clinical signs with a history of contact with other cats or dogs would suggest the involvement of ear mites. Although ear mites cause over half of all feline ear disease, other conditions can result in very similar clinical signs and must be ruled-out before treatment is begun.

A veterinarian makes the diagnosis by observing the mite. This is usually straightforward and may be done either by examination of the cat's ears with an otoscope or by microscopic examination of discharge from the ear. If the ears are very sore, the cat may need to be sedated to allow the ears to be properly examined and treated.

How are ear mites treated?

Three steps are required to treat ear mites successfully:

1.  Treat the ears of all affected and susceptible pets

2.  Treat the skin of all affected and susceptible pets

3.  Treat the indoor environment because the mite is capable of limited survival off pets

"It is necessary for the entire course of treatment to last a minimum of three weeks."

Your veterinarian will advise you about which insecticidal products are suitable. There are several ear medications licensed for the treatment of ear mites in cats. No medication can penetrate the eggs or pupae, so treatment is directed at killing the adult and larval forms. Because of the length of the life cycle, it is necessary for the entire course of treatment to last a minimum of three weeks. There are no products licensed for use on the house or on an animal's skin but many products licensed for flea control are effective.

Products most often used are topically applied once a month and have the added benefit of treating other parasites like fleas and roundworms as well. Your Veterinarian will prescribe the best product for you and your cat.

Your veterinarian may ask to re-examine the cat to ensure that the mites have been eliminated after the initial treatment has been performed.

Do ear mites affect people?

Ear mites may cause a temporary itchy rash on susceptible people if there are infested pets in the household. Eradication of the mites from the pets will cure the problem.