If your cat or kitten has itchy ears, you may have a new, if uninvited, pet in your home: ear mites (Otodectes cynotis). “Ear mites are the most common cause of ear disease in cats,” says Lluis Ferrer, DVM, PhD, DECVD, a professor of veterinary dermatology at the Tufts Cummings School of Veterinary Medicine. Fortunately, these nearly invisible parasites are “pretty to easy to diagnose, and quite easy to eliminate,” explains Dr. Ferrer.
The eight-legged arthropods look like tiny white dots — about a third of a millimeter, or one hundredth of an inch. They like ear canals, with their rich environment of wax, fats and secretions. Once they get inside, they multiply quickly — and jump to any other cat nearby. The infections are most common in kittens and young cats who play with each other, as well as cats that go outside and interact with other cats.
Cats that are most at risk
Cats in shelters, and strays, often get ear mites, too. “Young cats get in close contact with other cats, and they lick each other, so they’re more exposed,” says Dr. Ferrer. Once your cat gets infected, it’s likely to develop an allergic reaction to the mites — and that’s what really causes discomfort. “It leads to extreme itchiness — you’ll see your cat start to scratch his ears all the time.”
That’s what brings most cat owners to the vet. “Typically, we’ll see a brownish secretion, like coffee grounds, inside the ear canal or the ear entrance,” says Ferrer. Your vet will examine both ear canals with an otoscope, take a sample, and look at it under a microscope. “That’s when you see the mites,” he says. If there’s no evidence of ear mites, your vet will explore other common causes. (See related sidebar on this page.)
Fortunately, treatment is simple. For adult cats, and kittens over three months old, Dr. Ferrer prescribes the anti-parasitic medication selamectin (brand name: Revolution), which is applied on the skin between the shoulder blades and absorbed into the cat’s system. It can be reapplied every four weeks. “With one treatment, the mites are gone, but to be completely sure, we do it every month for two or three months,” explains Dr. Ferrer.
If you have more than one cat in your house, however, you can’t just treat the affected cat — all your cats should be treated to make sure the mites are eliminated from your household. “You have to treat all the cats living together,” says Dr. Ferrer. (For kittens three months and younger, Dr. Ferrer uses a different anti-parasitic medication that is applied topically to the ear canal and isn’t absorbed into the kitten’s system.)
Methods of prevention
What about prevention? If your cat is regularly around other cats, you may want to consider a systemic anti-parasitic treatment such as selamectin on a regularly, monthly basis. “It’s quite a safe medication,” says Dr. Ferrer. It also protects your cat against fleas and internal parasites.
“If you think your cat will be exposed to other cats, you can use the same medication year round as a preventive,” explains Dr. Ferrer. If that describes you, discuss year-round prevention with your veterinarian.
Avoid ear cleaning
One thing a cat owner doesn’t need to do, and shouldn’t do: Clean your cat’s ears. “Don’t use cotton swabs,” says Dr. Ferrer. “Just leave the ears alone. Only when there is a problem do we apply cleaning drops.” — Bob Barnett