Sarcoptes scabiei is recognized by the characteristic oval, ventrally flattened, and dorsally convex tortoise-like body, stout dorsal setae, numerous cuticular spines, and transversely ridged cuticular striations. Females have suckers on legs 1 and 2. The mite is the agent of scabies in humans and sarcoptic mange in nearly 47 hosts from 7 orders of mammals. Biological evidence indicates that there are physiological differences among scabies mites from different hosts and that a considerable degree of host specificity has arisen among populations of this parasite.
Males have suckers on legs 1, 2 and 4. Sarcoptes scabiei burrows into the epidemis of its host forming long tunnels in which the life cycle is completed.
The infestation usually begins in areas of minimal hair growth, such as the muzzle, around the eyes, and on the elbows; the lesions consist of follicular papules, areas of erythema, crusts of dried serum and blood, and excoriations from scratching to relieve the intense pruritus.
On cattle Sarcoptes scabiei is found more frequently on the sparsely-haired parts of the body such as the inner surface of the thighs, under side of neck and brisket, and around the root of the tail.
This mite is common in some rabbit colonies but is unlikely to be encountered in the laboratory except in stocks obtained from suppliers which do not have effective sanitation and parasite control programs. Lesions occur first on the head, ears, and legs and then become generalized.
On rabbits Sarcoptes scabiei is found more frequently on the sparsely-haired parts of the body such as the face, muzzle, ears, and legs.
Nowadays sarcoptic mange in pigs has been reported in all major swine producing countries and is prevalent in Brazilian swine herds. Lesions, or scabs, on the animals may start on any part of the body, but usually appear first on the head, around the eyes, nose, or ears; lesions may progress to hyperkeratosis and exfoliation of epidermal debris.