What is cheyletiellosis?
Also known as walking dandruff, cheyletiellosis is a highly contagious skin disease caused by the Cheyletiellosis mite. Cats are most commonly infected with Cheyletiella blakei. Infection occurs more often in young cats, although cats of any age can become infected.
The mites live out their entire life cycle (approximately 30 days) on the cat, living on the skin surface keratin. They occasionally burrow their head pincers (known as chelicerae) into the skin and feed on tissue fluids.
Transmission occurs via direct contact with an infected animal. Adult mites can survive for up to 2 days off the host, so your cat can become infected via the environment.
Often the mites can be seen moving around, hence the name ‘walking dandruff’.
Your veterinarian will perform a complete physical examination of your cat and obtain a medical history. It may be possible to see mites on the cat with a magnifying glass.
Your veterinarian may also perform the following tests:
- Skin scrapings: A skin scraping test uses a scalpel blade to gently scrape along the surface of the skin to look for the presence of inflammatory cells, cancerous cells, bacteria, skin parasites such as mites, parasite eggs, fungi etc.
- Flea combings: The veterinarian runs a fine comb through the cat’s fur to look for cat fleas or droppings.
- Acetate tape preparations: Clear acetate tape is firmly pressed onto the skin, samples are then stained and evaluated under a microscope for bacteria, yeast, mites, and inflammatory cells.
- Fecal analysis: Mites and or eggs may also be found in fecal samples
There are several ways to tackle cheyletiellosis, your veterinarian will recommend the best treatment.
- Weekly dipping with either lime sulfur or pyrethrin for 6 – 8 weeks. It may be necessary to clip cats with long hair.
- Ivermectin has not been approved for use in cats but is commonly prescribed extra-label to treat Cheyletiellosis.
- Treat the environment with a suitable insecticide.
Can humans become infected with walking dandruff?
Yes. Skin lesions have been reported in humans. 
 The Cornell Book of Cats – Faculty, Staff, and Associates Cornell Feline Health Center. Edited by Mordecai Siegal.