There are several types of mites that can invade the ear canals of cats. The same types of ear mites affect both cats and dogs. The most common type of ear mite is otodectes cynotis. Ear mites cause pruritis, or itching, of the ears, neck and head. Rarely, ear mites will bite humans, but they do not infest the human ear canal. Cats and dogs are the preferred hosts.
According to the website Pet Education, symptoms of ear mite infection include itching of the ears, neck and head; generalised itching; frequent head shaking; red-brown or black crust on the outer ear; scratches or redness on the back side of the ear; black or brown bumps in the ear canal; and crusting on the neck and tail.
According to the website EarMitesCats, a cat suspected of ear mite infection should be brought to the veterinarian. Diagnosis includes a complete physical exam including blood tests, an electrolyte panel and a urinalysis to rule out any other conditions. The cat's ear canal will be examined with an otoscope, and mites can be directly extracted with ear swabs dipped in mineral oil.
Ear mites are extremely contagious and can be rapidly transmitted from one animal to another. Outdoor pets are particularly susceptible; however, humans can introduce ear mites to the home on shoes or clothing, so even indoor pets should be monitored for potential infection. According to the website Vet Base, ear mites biting humans is so rare, that many veterinarians have never seen it happen in practice.
According to the Companion Animal Parasite Council, ear mites are easily treated with insecticide drops provided by a veterinarian. The most commonly used insecticide used to treat ear mites is pyrethrin. Once one animal in a household has been infected with ear mites, all other animals should be treated as a preventive measure.
Left untreated, ear mite infections can cause permanent hearing loss in cats. Ear mite infections can also lead to more serious secondary infections by bacteria or yeast, according to the website Vet Base. Chronic inflammation of the ear can lead to a ruptured ear drum and middle ear disease, which can cause the cat to lose its sense of equilibrium.