Today we continue discussing common parasitic causes of skin infections in pets by taking a look at the under-diagnosed mite, Cheyletiella species, which causes cheyletiellosis or "walking dandruff."Cheyletiella are mites that generally live on the skin, but there have been reported cases where they enter the nostrils and are found in the nasal passages. Three main species can affect various hosts: Cheyletiella yasguri usually affects dogs; Cheyletiella blakei usually infests cats; Cheyletiella parasitovorax affects rabbits. Although humans are not a natural host for this parasite, the mites can move onto people and affect us but because they cannot complete their life cycle on people, human infestations are considered transient or temporary. Infestation with Cheyletiella is also 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.
The adult mites are fairly large (about 0.385 millimetres long) and can sometimes be seen with the naked eye. They are yellow and have four pairs of legs with combs instead of claws, and prominent mouth parts that end in hooks. This anatomy means that they seldom burrow into the skin but instead live on the surface, where they feed on the keratin layer of the epidermis.
The life cycle is 21 days and includes five stages: egg, pre-larva, larva, first-and second-nymph stage, and adult. The eggs are fastened to pet hairs by cocoon-like strands and are often mistaken for hookworm eggs but are three times larger. Once exposure occurs, it can take three to five weeks for the infestation to develop. The female mite is able to live off the host in the environment for ten days.
Cheyletiellosis is contagious. The mites are often picked up from direct contact with another infested animal. However, since the mites and eggs can survive for a short time in the environment, infestations can be picked up indirectly by contact with bedding, grooming equipment, or other objects carrying the mites.A veterinarian must diagnose the presence of the mites or their eggs by taking scrapings of the skin, or samples of the dandruff caught on sticky tape or gathered by a fine comb, and examining the samples under a microscope. The eggs can also sometimes be found in fecal samples because they are swallowed during self-grooming behaviour.The symptoms of Cheyletiella vary between animals with some showing no signs at all, and others itching or scratching intensely. Lesions occur primarily on the back. Other symptoms may include flaky skin (dandruff), reddened skin, small bumps on the skin, scabs on the skin, and mild hair loss. If the mites go into the nose, the animal may also scratch at the face and sneeze frequently.
Symptoms in humans include multiple red, itchy bumps on the arms, trunk and buttocks; face rubbing and sneezing. Humans are an irregular host for the mite, so the symptoms usually go away in about three weeks. Symptoms on people should resolve once mites are cleared from the household pets.There are several options for treating cheyletiellosis including topical treatments such as sprays, shampoos and dips; oral parasite preventatives and injections but your veterinarian must first diagnose the mite before he or she recommends a treatment programme appropriate for your pet.All pets in the home should be treated at the same time regardless of if they show symptoms or not, because they may be carriers of the mites. In addition to treating your pets, the environment (floors, bedding, toys etc.,) must be treated since eggs and adults can survive temporarily without a host. It is very important that you follow your veterinarian's advice on which products to use for cats and dogs, and for applying these products safely.
Copyright � Kristel-Marie Ramnath 2014. For further information contact 689-8113 or bestpetsbehave@hotmail.com