Ear mites are a common parasite in pets, wildlife and other domestic animals. On very rare occasions they can infect humans, too.

There may be as many as 48,200 species or more of the tiny critters. While this column deals mostly with cats, be advised ear mites are highly contagious, spreading from contact with another animal that has an infestation. If Kitty has ear mites, one may want to look in Rover’s ears, too, and any other mammals living in the household.

An external parasite, ear mites live on and feed off the host. The species most common in cats and dogs is Otodectes cynotis. When mites colonize the ears, the infestation is medically called otoacariasis.

Most owners are tipped off that something is wrong when they notice their cats repeatedly shaking their head or scratching at their ears. If this continues long enough, the skin will be injured, become inflamed and may develop a secondary infection.

A look inside the external ear canal will typically reveal inflammation of the tissues and dark brown or black granular debris. A close look, possibly with the naked eye but usually with an otoscope, reveals the tiny insects. They are about the size of a pinhead.

Many times, people assume their cat or dog that scratches at their ears has ear mites. And in many cases, they are wrong. They may begin at-home treatment for ear mites with over-the-counter medications when the poor animal is suffering with a bacterial or yeast infection.

It is better for most owners to have their pets’ ears checked by a veterinarian to confirm what is going on and begin appropriate treatment. If you have a pet that has chronic ear mite infestations, your veterinarian will often help you begin prevention or care with just a phone call after an initial visit to confirm the infection.

The exudate in the ears mentioned above is often said to resemble coffee grounds. That material is a composite of blood, ear wax, inflammatory chemicals and the bodies of the mites themselves. The mites feed on ear wax and skin oils, called sebum.

The sebaceous glands in the middle layers of the skin produce sebum. Interestingly, sebum comes to the surface of the skin through holocrine secretion. As specialized cells, called sebocytes, die as programmed genetically, they liquify and release sebum into the glands. The waxy/oily material then is pushed up to the surface by nearby growing hair follicles.

Once ear mites are confirmed, there are a variety of treatments your veterinarian may offer. Without getting into specific products, know that most veterinarians who deal with common diseases like this develop a treatment program that has been very successful for their location and practice.

This is the best reason to take your pets to a veterinarian, at least initially. Let him or her make the diagnosis and you follow the treatment plan closely afterwards. Beyond that, your veterinarian may trust that you have a repeat infestation (which is common), and let you work with the practice to resolve the matter as it occurs.

There are many products available for ear mite eradication. Each category takes a varying length of time to work, as long as three weeks in some cases. Others are effective and work much more quickly but present different and potentially important risks.

Many of these products used to require a prescription and are now available over the counter. Without proper screening of your pet, some of the most effective products can be deadly. Trust your veterinarian to discuss which product is best for your pet, for you to administer and provides a margin of safety.

Powell, of Pullman, retired as public information officer for Washington State University’s College of Veterinary Medicine in Pullman. This column reflects his thoughts and no longer represents WSU. He may be contacted at charliepowell74@gmail.com.