What are ear mites in cats?
Ear mites, also known as Otodectes cynotis, are tiny parasitic insects that live on the skin surface inside a cat’s ear canal. An infestation of ear mites is called otodectic mange (source).
Cats usually get ear mites from close contact with another infested cat or kitten. The mites quickly spread from cat to cat through social behaviors like mutual grooming. Mother cats also frequently pass ear mites on to their kittens (source).
Common symptoms of an ear mite infestation include excessive head shaking and scratching at the ears. A dark crumbly discharge resembling coffee grounds may be present in the external ear canal. Severe infestations can cause scabbing and wounds on the skin surface of the ear canal (source).
Diagnosing Ear Mites
Ear mites can be diagnosed through visual inspection of a cat’s ears and microscopic examination of ear discharge. According to the Small Door Veterinary, examining a cat’s ears with an otoscope allows a veterinarian to look down the ear canal for signs of irritation and the presence of mites or eggs. Dark coffee-ground looking debris in the ears is also indicative of ear mites.
As the VCA Hospitals explains, taking a sample of ear discharge and examining it under a microscope can confirm the diagnosis by revealing the presence of mites. The mites will appear as tiny white specs moving around in the sample. This is usually a straightforward way for a veterinarian to diagnose an ear mite infection.
Risks of ear mites
Ear mites can lead to some serious health complications if left untreated in cats. The most common risk is development of ear infections, known as otitis externa. The ear mites and their debris irritate the ear canal, leading to inflammation, redness, and bacterial or yeast overgrowth. These infections cause significant pain and discomfort. They require veterinary treatment with medications like antibiotics, antifungals, and steroid ointications to resolve the infection and inflammation.
In addition to ear infections, ear mites can also cause damage to the ear canal itself. The inflammation and debris can lead to thickening of the ear canal skin and changes to normal anatomy. In severe cases, the ear canal may become narrowed or obstructed leading to decreased hearing. The mites can also puncture the eardrum, leading to middle ear disease.
Ear mites may also lead to behavioral changes in cats. The intense itching leads to scratching, head shaking, and discomfort. This can cause anxiety, lethargy, loss of appetite, and overall irritation in cats. Cats may damage their ear canal and pinnae (ear flaps) from the vigorous scratching. So it’s important to resolve ear mite infestations quickly before secondary damage sets in.
One Time Ear Mite Treatments
There are a few medications that can effectively treat ear mites in cats with just a single dose:
Selamectin (Revolution)
Selamectin is a topical medication that kills ear mites and prevents reinfestation for at least 30 days after application (1). Revolution is applied to the skin on the back of the cat’s neck and is absorbed into the bloodstream, killing ear mites as well as heartworms, fleas, roundworms, and hookworms.
Ivermectin
Ivermectin is an oral medication that can kill ear mites with one dose (2). It paralyzes and kills the mites by interfering with their nervous system. Ivermectin should only be administered under the supervision of a veterinarian to avoid overdosing.
Milbemycin Oxime
Milbemycin oxime is another oral medication that is effective against ear mites. It is often combined with lufenuron in medications like Sentinel to kill fleas as well (3). Like ivermectin, milbemycin oxime should only be given under veterinary supervision.
While a single dose of these medications may kill all the live ear mites, owners will still need to thoroughly clean the cat’s ears to remove debris. Follow up exams and additional medications may be needed to ensure the infestation has been fully eliminated.
(1) https://www.petfinder.com/cats/cat-health/ear-mites-cats/
(2) https://www.amazon.com/Best-Ear-Mite-Medicine-Cats/s/ref=nb_sb_noss_1
(3) https://bngmiraclepet.com/products/cat-ear-treatment-kit
Selamectin (Revolution)
Selamectin is the active ingredient in Revolution, a topical medication used to treat and prevent ear mites in cats. Revolution kills ear mites and eggs with a single topical dose applied between the shoulder blades. In addition to treating ear mites, Revolution also protects against fleas and some intestinal worms like roundworms and hookworms [1].
Revolution is very effective because selamectin is absorbed into the bloodstream through the skin and provides whole body protection. It starts working within 24 hours and provides month-long protection with a single dose [2]. Since it treats multiple parasites with one medication, Revolution can eliminate an ear mite infestation while also preventing reinfestation by fleas or worms.
Revolution requires a prescription from a veterinarian. It has minimal side effects but can occasionally cause temporary hair loss, irritation, or drooling. It should not be used in sick or weak cats. Overall, Revolution is a convenient and effective one-time ear mite treatment that also provides ongoing parasite prevention.
Ivermectin
Ivermectin is an oral medication commonly used to treat and kill ear mites in cats. It can be very effective at eliminating ear mite infestations when given properly.
Ivermectin works by paralyzing and killing the ear mites. It is available as tablets or a topical ear treatment. The oral form is most commonly prescribed, as it circulates through the body and kills mites systemically. According to the VCA Hospitals, oral ivermectin is given once daily for 10-14 days to kill adult ear mites. It may take several weeks to fully eliminate a severe infestation.
While generally safe when prescribed by a veterinarian, ivermectin can be toxic at high doses, especially in cats with the MDR1 gene mutation. Potential side effects include vomiting, diarrhea, weakness, dilated pupils, unsteadiness, and even seizures. Cats should be tested for the MDR1 mutation before giving oral ivermectin. The medication should only be administered under veterinary supervision.
Milbemycin Oxime
Milbemycin oxime is an oral medication that is effective for treating ear mites in cats. It contains milbemycin oxime as the active ingredient and comes in tablet or liquid suspension forms. According to the product label, milbemycin oxime kills adult ear mites as well as the eggs and larval stages to break the mite life cycle [1]. A single oral dose is usually all that is needed to completely eliminate an ear mite infection, providing an easy one-time treatment.
In addition to treating ear mites, milbemycin oxime is also effective against some intestinal worms like hookworms, roundworms, and whipworms [2]. So it serves as a dual dewormer and ear mite treatment in one product. Potential side effects are uncommon but can include lethargy, vomiting, and diarrhea.
Other Treatments
While some treatments like selamectin and ivermectin can fully eliminate ear mites in one dose, other options may require repeat applications to clear infestations. This is because ear mites can be persistent and some medications may not penetrate deep enough into the ear canal to fully eliminate the mites in one dose.
Common repeat treatments include:
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Topical medications like pyrethrins, which can kill ear mites but often require 2-4 weekly treatments. These are applied directly into the ear canal.
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Oral medications like milbemycin oxime may require 2-4 weekly doses. These are given orally in pill or liquid form.
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Ear drops with ingredients like tannic acid or thymol can help smother and kill ear mites but need to be applied daily for 7-30 days. These liquefy built-up debris and wax while suffocating the mites.
The main downside of repeat treatments is the extended duration required to fully eliminate infestations. However, some cats tolerate certain topical or oral medications better than single-dose options. Under a vet’s supervision, repeat medications present another effective ear mite treatment path.
Environmental Control
Thoroughly cleaning the cat’s environment is an important part of treating ear mites. The mites can survive for several days without a host, so it’s critical to eliminate any traces of them in the home.
Wash all bedding, blankets, pillows, toys, etc. that the cat has come into contact with using hot water. The heat will help kill any lingering mites or eggs. Vacuum all carpets, furniture, curtains, and hard floors thoroughly as well. Pay close attention to crevices and corners where debris can collect.
Disinfect any solid surfaces the cat frequents like countertops, windowsills, and cat towers. An over-the-counter disinfectant or diluted bleach solution can be used. Be sure to rinse afterward.
For extreme cases, some vets may recommend discarding infested bedding altogether and replacing scratching posts or cat towers if proper disinfection isn’t possible. This can help prevent reinfection after medical treatment.
Regular vacuuming and disinfecting should continue for 2-3 weeks after the cat’s initial ear mite treatment. This will help ensure the environment is completely free of mites so reinfection does not occur.
Prevention
There are a few key ways to help prevent ear mites in cats:
Regular flea control is important, as ear mites can spread from fleas. Using monthly topical flea prevention medication like selamectin or fipronil can help break the flea-ear mite cycle.
Avoid contact with cats that may be infected with ear mites. This includes stray cats as well as cats that go outside. Indoor cats are at lower risk of exposure.
Clean bedding and toys regularly to remove any mite eggs that may be present. Wash items in hot, soapy water.
Check your cat’s ears regularly for any signs of irritation or excess debris/wax which could indicate an infection.
