Ear mites (Otodectes) are commonly found in the external ear canal of dogs and cats. These pests cause an itching sensation that results in the pet shaking its head or scratching its ears and thereby spreading the parasite to other hosts. Once inside the external ear canal the adult mite will feed on the pet’s blood supply from the tissues that line the canal. The adult will then lay its eggs that will hatch in a short time (3 weeks) and feed again until a large number of mites are present. Although this parasite can be transferred from cat to dog and vice versa it is not transferred to humans.
The diagnosis of ear mites is made when the mite is directly visualized under a low power of magnification. The size of the mite is approximately the size of a grain of sand. The normal ear canal has little to no debris in it; however, when ear mites are present there is usually a significant amount of black debris present. The black debris is the pet’s blood that has been digested and then excreted by the mite. The debris is also dry in appearance unless there is a secondary infection present.
Treatment consists of removing the debris and killing the mite and its eggs. Using a topical medication that contains an insecticide for a long enough period of time traditionally will kill the mite. A new, single use, FDA approved treatment uses a topical product to kill the mite as it feeds from the host. Some of the old less effective home remedies such as mineral oil can be used to suffocate the mite if it is done over a long period of time.
The adult mite can live outside the ear canal for some time. Thus any treatment to be successful must either include a bath of the pet or treatment for a long enough period to kill any return visitors. Treating both ears may also be a good idea as the mite can crawl back and forth from one canal to the other. Due to the widespread nature of this parasite it is difficult to prevent this parasite problem from occurring. The best advice is to treat those that are infested as early as possible. As always it is best to let your veterinarian confirm the diagnosis so that proper treatment can be given and thus avoid treating with the wrong medication.