Cheyletiella

موضوع: Cheyletiella الخميس ديسمبر 02, 2010 1:45 pm

Cheyletiella

[ندعوك للتسجيل في المنتدى أو التعريف بنفسك لمعاينة هذه الصورة]

Cheyletiella are mites that live on the skin, causing irritation, dandruff, and itchiness. A distinguishing feature of this mite species are the large, claw-like mouth parts. These mites can be found quite commonly on cats, dogs and rabbits, and other species. Though humans are not a natural host for this parasite, Cheyletiella mites can happily live on humans for a while, causing an itchy rash.

Infestation with Cheyletiella is also sometimes called "walking dandruff," since the movement of the mites among the flakes of skin tends to make it look like the dandruff is on the move. Medically speaking, infestation with Cheyletiella mites is called Cheyletiellosis.

Sometimes Cheyletiella is also called the "rabbit fur mite," but there are actually several species of Cheyletiella that tend to prefer different species of host.

Identifying the Cheyletiella species involved is irrelevant, however, as the symptoms and treatment are identical for the different Cheyletiella species, and the mites sometimes cross over to other host species given the chance. They will also move onto people, though they don't complete their life cycle on people so human infestations are considered transient.

Though Cheyletiella generally live on the skin, there have been cases where they enter the nostrils and hang out in the nasal passages, too.

Transmission

The mites are often picked up from direct contact with another infested animal. However, the mites and eggs can survive for a short time (days to weeks) in the environment so infestations can be picked up indirectly by contact with bedding or other objects carrying the mites.

Signs and Symptoms of Cheyletiella
The symptoms of Cheyletiella vary between animals (some have no symptoms at all) and occur primarily on the back, and may include:

flaky skin (dandruff)
scratching (itchiness)
reddened skin
small bumps on the skin
scabs on the skin
mild hair loss
if they mites go into the nose, sneezing and scratching at the face may also be present

Diagnosis of Cheyletiella

Though sometimes Cheyletiella mites can be seen moving about on the skin, in many cases they can be quite difficult to find. Scrapings of the skin, or samples of the dandruff caught on sticky tape or gathered by a fine comb, can be examined for the presence of the mites or their eggs. Their eggs can also sometimes be found in fecal samples because they are swallowed during self-grooming behavior. However, none of these methods are foolproof and the mites may not be "caught" even when they are present, especially in cats.Cheyletiella may be strongly suspected based on the signs and symptoms, so even if the mites can't be found, your vet may still recommend treating for Cheyletiella. Trial treatment is a good way to rule out Cheyletiella before moving on to investigate other causes of skin problems, which can be difficult to sort out.

Treating Cheyletiella

[/b]There are several options for treating Cheyletiella, and your vet will recommend a treatment appropriate for your pet and household situation. In addition to treating the pet, the household environment (floors, bedding, toys, etc.) must be treated as well. Your vet can offer advice on treatment of the home environment.All pets in the home should be treated at the same time, as it is possible for them to carry Cheyletiella without showing symptoms. Treatment options include:

selamectin (e.g. Revolution®): selamectin (a parasite preventative applied to the skin) is effective at treating Cheyletiella.
milbemycin (e.g. Interceptor®): an oral parasite preventative has also been used in cats and dogs to treat Cheyletiella.
ivermectin: can be given orally or by injection. The doses required have caused adverse reactions, however, especially in some herding breeds of dogs along with a few other breeds, as well as occasional sensitive individuals.
topical treatments such as sprays, shampoos, and dips: Cheyletiella responds fairly well to topical treatments effective against mites (e.g. pyrethrin-based products, lime-sulfur dips). It is very important follow your vet's advice which products to use for cats and dogs, and for applying these products safely. These treatments are time-consuming, and if mites take refuge in the nasal passages, topical treatments will not be as effective as the above medications, which are absorbed into the body.

Cheyletiella infestations on people are self-limiting since the mites won't reproduce on humans. Symptoms on people should resolve once mites are cleared from the household pets.