Cheyletiellosis in Cats
An infestation of the Cheyletiella mite is medically referred to as cheyletiellosis. The Cheyletiella mite is a highly contagious, zoonotic skin parasite that feeds on the the keratin layer of the skin — the outer layer — and on the tissue fluid of the top layer. This parasitic skin condition is similar to a flea infestation, and is treated with the same products, and with the same environmental methods used for exterminating fleas. Prevalence varies by geographic region largely because common flea-control insecticides control it. These mites mainly infect cats and dogs, but because the Cheyletiella mite can live off of other hosts, it is transmittable to humans.
A Cheyletiella infestation is also referred to as "walking dandruff," because of the way the mite maneuvers around beneath the keratin layer, pushing up scales of skin so that they seem to be moving, and leaving a dusty surface of skin scales on the surface of the hair. The mites generally cause moderate irritation, but in young cats this infestation can be more severe when coupled with skin abrasions, and an increased risk of infection due to an immature immune system.
Symptoms and Types
- Alopecia
- Excessive grooming
- Excessive scratching
- Visible scaling of the skin
- Dusting of skin flakes (dandruff) on the surface of the hair
- Lesions on the back
- Underlying skin irritation (may be minimal)
- May experience bilaterally symmetrical hair loss
- Small yellow skin mite may be visible on close inspection
Causes
- Frequent contact with other animals
- Recent stay in animal shelter, breeding establishment, grooming establishments, kennel
- Mites may be picked up in an environment apparently lacking animal presence
- Re-infestation from improperly decontaminated bedding or housing
Diagnosis
Other conditions that have similar symptoms are dandruff, flea-allergic skin irritation, infestation by mites other than cheyletiella, allergy due to food sensitivity, diabetes, and skin allergies that are particular to your cat. Even so, it is general practice to test for cheyletiellosis when any of the obvious symptoms are present.
Your veterinarian will take samples of skin and debris from the top layer of the skin and hair for examination. Even if the mites are not readily visible by looking at the cat, they are large enough to be discovered with a simple magnifying lens. The process is straightforward: the mites are easily collected by scraping a sample of skin, or by using a piece of tape to lift loose skin. They can also be found in a stool sample, since they are frequently ingested during grooming and passed through the digestive tract undigested. If cheyletiella mites cannot be identified for certain, your veterinarian may want to test your cat's response to insecticides.
Treatment
When a cat has been diagnosed with cheyletiellosis, all of the animals in the household must be treated, as the mite can live for up to 10 days away from a host. It is also important to thoroughly clean bedding, kennels, and rugs, so that the mite does not re-infect your cat, or infect other pets. Your cat must then be bathed six to eight times a week in lime-sulfur rinses so as to remove skin scales. In addition to insecticide and lime-sulfur rinses, your veterinarian may also prescribe oral medications. If your cat has a long coat, it will need to be clipped to a short length to make treatment more effective.
Living and Management
If you have been in contact with an infected animal, or your cat is infested with the Cheyletiella mite, you may also develop a reaction, such as itching, small red bumps, or minor lesions, but the condition will clear on its own through the normal course of bathing yourself. To prevent the recurrence of mites, you will need to disinfect your cat and its living environment, as well as its combs, brushes, and other grooming equipment.
If the treatment regimen does not work, your veterinarian will look for other causes for the symptoms. Re-infestation may come from another local carrier, or from the presence of an unidentified source for the mites, such as untreated bedding.