Sarcoptic mites burrow into the skin. Each female makes a gallery in which she lays her eggs. The skin over and around the burrow or gallery becomes irritated and inflamed, with a small cone-shaped swelling. The demodectic mites are very small and carrot-shaped. They live in the hair follicles and oil glands, producing small, spherical, hard swellings.
Sarcoptic mange is the common mange in hogs.
Traffic in breeding stock plays an important part in spreading the disease among hogs. Like scabies in other animals, it spreads rapidly under favorable conditions unless active control measures are taken. Although pigs, young growing stock, and poorly nourished old animals of low vitality suffer most from its ravages, sarcoptic mange often attacks vigorous mature hogs. The losses from this mange are due to irritation, arrested growth, unthrifty condition, lowered vitality, functional disorders, and high death rate. The mites penetrate the upper layer of the skin and excavate burrows, or galleries, in which the eggs are laid.