Mites and lice are an uncommon cause of skin disease in horses in many areas. A mite infection is called mange and a lice infection is called pediculosis. Typically itching (pruritus), scaling, and hair loss occur with mite infections usually being intensly pruritic. Without specific treatment the disease will usually worsen and can spread making an early accurate diagnosis or rule out of these parasites important. There are a large number of different skin parasites of horses and some have diverse diagnostic and therapeutic recommendations. This article presents the diagnosis, identification, life cycle and treatment of these pests. Illustrations are included.

The parasitic lice and mites life cycle have some common features. In general they reproduce on the horse with the female laying egges daily and completing their life cycle every 8 to 30 days. Whereas mites have species preferences they are not absolutely specie specific and may leave the host and contaminate the environment and other species. Lice on the other hand are specie specific and do not tend to leave the host and die within days of doing so however dislodged eggs may survive up to 3 weeks off the host. It is important to note that the eggs are resistant to treatment so it must be repeated weekly to every 2 weeks for 4 weeks.