Acariasis(redirected from demodectic acariasis)
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or mange, a chronic disease of animals, accompanied by itching and inflammation of the skin. It is caused by intracutaneous parasites, or itch mites. These mites are strictly specific to each species of farm animal. Infestation with acariasis occurs through contact between infested animals and healthy ones, as well as through mite-infested equipment used with the animals. Acariasis is most common during the autumn and winter seasons. Dirty, damp, cold, and dark quarters, indifferent care, and unbalanced feeding of the animals are the factors which contribute to the occurrence of acariasis. Young animals and emaciated animals are more susceptible to acariasis than others. The parasites live between four and six weeks on the host’s body. In working their way into the skin, they irritate the nerve endings. The animals scratch the itching areas and the skin thickens, becomes bald, and loses its elasticity. Cows and sheep grow thin, and their productivity declines.
The choice of a medicine and a method of treatment depends upon the nature of infestation of the skin, the condition and species of the animal, and the season. Horses are usually fumigated in special chambers with sulfur dioxide, and other animals with limited infestations are treated with salves containing medicines which kill the parasites. To treat or prevent mass infestation, the animals are washed in baths specially built in the ground which contain an emulsion of the antiparasite agent (for example, hexachloran or creolin). At the same time, the quarters in which the animals are kept, the equipment used with them, and overalls are also disinfected. Since the agents used for treating acariasis are usually not effective on the eggs of the parasites, the animals are re-treated according to the development cycle of the mites.
With the appearance of acariasis on a farm, the animals are divided into three groups: the infected, those suspected of infestation, and the healthy. Each group is kept in isolation from the others and is tended by a staff assigned to it. The farm is considered to be free of infestation if no new cases of infestation have appeared for 20 days after the preventive and therapeutic measures have been carried out.