Overview of Mites
Mites are very small arthropods, with more than 30,000 described species, and possibly another 450,000 still unidentified. Most mites are not parasites but free-living predators that occupy just about every type of habitat on earth. The small number that are parasites live on the skin of mammals and birds, and feed on blood, lymph, skin debris, and skin secretions. Ectoparasitic mites spend their entire life cycle living on their host.
An ectoparasitic mite infestation is called acariasis and can cause severe dermatitis known as mange. The most common ectoparasitic mites on pets are Otodectes (ear mites), Sarcoptes (scabies), and Demodex (demodectic mange).
Ear mites can cause an allergic reaction resulting in intense itching (pruritis) of the ear. Ear mites can affect dogs and cats of all ages and are very common in puppies and kittens. They leave thick, reddish-brown or black crusts on the outer ear and sometimes cause crusting and scales on the neck, rump, and tail. Secondary infections often occur as a result of the pet scratching or biting itself, to relieve itching.
Ear mites are very contagious, so it is important to treat the pet and the pet's environment. The pet's ears should be thoroughly cleaned with mineral oil (or an ear cleaner recommended by the veterinarian). A prescribed topical or systemic medication may then be applied.
Ivermectin can be administered either systemically (once every other week for 2 to 4 weeks) or directly into the ear canal (once every other week for 2 treatments). Dogs with heartworm may experience a reaction to this drug. Ivermection should not be used in collies, shelties, other herding breeds, or in pets younger than 4 weeks of age.
A pyrethrin-based flea spray can be used to treat the entire animal weekly for 4 to 6 weeks. Pyrethrin is a natural chemical derived from chrysanthemums and is safe for pets of all ages.
Rotenone-based products are used on the ear twice a week, then weekly; to prevent recurrence they should be used for 2 weeks after clinical symptoms disappear.
The pet's environment should be thoroughly cleaned and treated with an indoor fog or spray twice, 2 to 4 weeks apart.