Ear Mites in dogs


Ear Mites

Ear mites, (Otodectes cynotis) is the most common ear mite of cats butcan be a problem for dogs. It usually lives in the ears and on the headof affected cats or dogs but it can sometimes live on the body of the cator dog. It is contagious and the presence of the mites can cause severeinflammation in affected cat or dog's ears.

Ear mites are not the only cause of ear disease in cats and dogs. Yourpet should be examined to determine if ear mites are present prior to treatment.Whenever treatment for this condition is not working well other causesof ear disease should be considered.

In the past it was felt that ear mites did not live well off the petbut they may be better at surviving in the environment than we thought.In order to eliminate ear mites it is important to treat your cat's ordog's ears, the haircoat and the pet's environment for the mites. Thereare a number of approved medications for ear mites. Flea control productsthat kill adult fleas will kill mites. These may be used to treat the haircoatand the house, according to the product directions. In particularly stubborncases, the use of ivermectin, an experimental drug in cats, may be justified.

Mike Richards, DVM

Ear mites

Question: My dog has ear mites. What are these and howdid she get them?

Answer: Ear mites are an external parasite that can infectdogs, cats and morerarely, humans. The mite's name is Otodectes cynotis. Otodectes mitesarelarge enough that they can sometimes be seen with the naked eye andare easyto see with magnification.

Ear mites live in the ears and on the skin of pets infected with them.Themite lives its entire life on the pet and it takes about 3 weeks fora miteegg to develop into an adult mite. The adult mites are very mobileand canlive for some time off of a dog or cat, which enables it to be fairlycontagious.

The most common sign of ear mite infection is shaking of the head andears.Dogs may also scratch at their ears, rub their face and in severe casesmayeven cause bleeding sores behind their ears in their effort to relievethediscomfort from the mites. The intense itching associated with thesemitesis thought to be due to a hypersensitivity reaction, which is similarto anallergy. Some pets can be infected without showing signs of itchingor headshaking, apparently because they don't develop the hypersensivity reaction.

Ear mites are more commonly diagnosed in cats than they are in dogsbut theyare a significant cause of ear infections in dogs, too. Dark brownto blackdebris accumulates in the ears of infected pets and the mites may bevisibleas small moving white specks on the debris. Secondary infection withbacteria or yeast is common in ear mite infections and may complicatethediagnosis. The mites can live on the skin and some dogs and cats appeartohave infections that affect only the skin, causing small sores to developinaffected areas. It is important to treat the ears for mites and thewholepet with a product that is capable of killing the mites. Most fleaand tickproducts will kill ear mites on the skin.

In multiple pet households it is important to treat all the pets andtoclean the environment, considering the use of premise control insecticidesin persistent cases. Ear mites are susceptible to many medications,including pyrethrins, rotenone, fibronil, thiabendazole and ivermectins.Itis necessary to treat for at least three to four weeks in most instancestobe sure to kill the adult mites and any eggs that may hatch later.

Many veterinary clients treat their dog's ears with over the counterproducts for ear mites based on the presence of ear inflammation orexudatein the ears, doing this for weeks or months prior to giving up andhavingtheir dog's ears examined. There are a number of causes of ear infectionindogs and it is best to have your vet examine your dog's ears to determineifthe cause of ear irritation is ear mites or another infection. Doingthiscan save your dog from weeks of pain or discomfort.

Mike Richards, DVM7/17/99


Michael Richards, D.V.M. co-owns a small animal general veterinary practice in rural tidewater Virginia. Dr. Richards graduated from Iowa State University's College of Veterinary Medicine in 1979, and has been in private practice ever since. Dr. Richards has been the director of the PetCare Forum...