Ear Mites in Dogs and Cats
Ear mites (Otodectes cynotis) are common parasites that live in the ear canal of dogs and cats. Most pets that are suffering from an ear mite infestation will have head shaking, scratching/digging at their ears, and/or dark brown debris in their ears. Ear mites are contagious and they can spread to other dogs and cats within the household.
These microscopic white insects can infest at any age, but are more common in younger animals. Mites not only affect the ears, but can also spread to the skin, resulting in itching on the back, neck, and tail areas.
They typically spend their entire lives on or within their host. The female lays her eggs in the ear and in the surrounding fur. These eggs hatch after a four-day incubation period, and the larva feeds on ear wax and skin oils for about one week. It then molts into a “protonymph,” which in turn molts into a “deutonymph.” This deutonymph does not develop a gender until it mates with an adult male. If the result is a female, she will be laden with eggs. The whole process from eggs to adult mite to reproduction is about three weeks.
Diagnosis of Ear Mites
A diagnosis of ear mites in dogs and cats starts with a thorough physical exam by a veterinarian and a complete medical history. Symptoms of ear mites often mimic other ear diseases. Your veterinarian needs to rule out other underlying diseases and may need additional diagnostics to confirm the presence of ear mites.
Additional testing may include:
- Otoscopic Exam. This uses a light and an ear cone to better evaluate the ear canal.
- Cytology Exam. This involves taking a sample of the ear discharge and examining it under a microscope. A swab is mixed with mineral oil and placed on a microscope slide. The ear mites can usually be observed through this test.
- A skin scraping may also be performed if your dog shows general skin lesions.
Pets with recurrent ear infections, those who respond poorly to treatment, pets with generalized skin abnormalities, or those with other health problems, may need additional diagnostic tests. These tests are not typical with simple ear mite infections.
- Complete blood count (CBC) and biochemical profile. Blood tests may be completed to check for contributing factors to the infection as well as to determine the presence of a concurrent disease.
- Culture and sensitivity. This test is helpful in diagnosing bacterial infections. The procedure involves taking a sample of the ear discharge and sending it to a laboratory to identify the specific bacteria present. The bacteria are exposed to multiple antibiotic samples to determine what will kill them most effectively.
- Radiographs (X-rays) or CT scans. These may be done to determine the health of the ear canal and bone, and may be used to evaluate the extent of involvement.
- Allergy tests. Your veterinarian may want to determine if your pet has allergies that may irritate the ears, as well as the skin.
Treatment of Ear Mites
Ear mites should only be treated after a veterinarian has made an expert diagnosis. If there are no mites, using anti-mite preparations may aggravate an infection in the ear.
Full treatment consists of the following:
- Cleaning the ear. Cleaning is the mandatory first step in treatment. If the exudate is not removed, it will keep the drops from affecting the mites directly. Moderate to severe infections may require sedation and in-hospital flushing. Do not use cotton swabs in the ear, these may push infection and discharge deeper into the ear canal.
- Applying medication to infected ears. Topical therapy usually consists of medication that you place in your pet’s ear once or twice daily in the form of drops. The specific medicine and directions will depend on the product used. Tresaderm® is an ear medication that has antibiotics to treat bacterial ear infections, cortisone to help with inflammation, and thiabendazole, which is used to treat mites and yeast. Tresaderm needs to be used for 10-14 days to clear all life cycles. Other drugs that might be prescribed to be used in the ear canal include milbemycin (Milbemite®) and ivermectin (Acarexx®). These two medications are single use only. Be sure to have your veterinarian show you how to place medication into your pet’s ears.
- Applying medications topically. There are a few topical medications that are used to treat ear mites. These medications are placed between the shoulder blades of pets and are absorbed across the skin. They also treat other pathogens such as fleas and GI parasites. Revolution® plus, which can be administered to cats or dogs, uses selamectin as the active ingredient. This medication treats fleas, ticks, ear mites, heartworms, GI parasites, hookworms, and roundworms. Advantage Multi® is manufactured for both dogs and cats, and uses moxidectin to treat ear mites, fleas, heartworms, hookworms, and roundworms. These medications need to be prescribed by a veterinarian and dog products should NEVER be used on cats. Using dog products on cats can lead to life-threatening reactions.
- Oral medications. There are a few oral medications that your veterinarian can prescribe for dogs to prevent ear mites. These cannot be used in cats. These medications fall into a category called isoxazoline products, better known as Simparica®, Nexgard®, Bravecto®, and Credelio®.
- All of these products need to be continually used to prevent infection or reinfection. None have lasting immunity against ear mites.
The best way to prevent your pets from getting an ear mite infection is to avoid exposure. Because they are contagious between pets, avoiding interaction with other animals that may have ear mites (feral/outdoor animals) will limit spread. Also, keeping your pets on a monthly preventative, such as the topical medications discussed above, can prevent infection.
Can Humans Get Ear Mites?
Dogs and cats cannot give humans ear mites. A skin rash/irritation has been noted in humans with pets suffering from ear mites, but this is relatively uncommon. Your primary human physician should be contacted if concerned about ear mites or other medical ailments.