Mites transferring from other animals, such as dogs and pigs, may cause an irritating itch in man. The infestation usually lasts for only two or three weeks. It can be distinguished from the human form because only a few mites are present, and these do not form tunnels. Mites pierce the skin to feed on tissue fluids. Their feeding and burrowing activities produce an irritation which causes intense itching.
Affected animals rub against posts, trees, and feeder bunks.
Animals may rub sometimes to the point of bleeding. The resulting injury to the skin is accompanied by a fluid exudate which hardens to form crusts on the surface of the skin. This crust formation is why the condition is known as scab or scabies. The skin becomes thickened, and may take on an elephant skin appearance. Affected animals lose much grazing time and loss of condition and production may be considerable.