Mites, a species of parasites, infect the skin and bodies of horses. They cause a condition called mange, in which the horse's skin becomes very itchy and breaks out in lesions. If the condition persists, the horse will scratch itself until the hair is rubbed off of the affected areas, and the skin may scab. Easily spread between horses, mite infestations require active treatment.
Types of Mites
Five different species of mites cause mange in horses. These include the sarcoptic mange mite, affecting the horse's head and neck; the psoroptic mange mite, affecting the withers, mane and shoulders; the chorioptic mange mite, affecting the lower legs; the demodectic mange mite, affecting the neck and shoulders; and the straw itch mite, affecting almost any area of the horse's body. Most mites bury underneath the horse's skin and begin laying eggs, though the chorioptic mange mites live and feed on the surface of the skin.
Mites live on long grasses and are then caught up on the horse's legs, where they travel up the horse's body. This makes horses with lots of feathering on their legs, such as many draft breeds, very susceptible to picking up mites. Mites can also be found in bins of stored feed, where they spoil the feed and often leave a fine dust on the feed's surface. Once infected, infestations can pass from horse to horse by means of physical contact, or through brushes used on multiple horses.
Symptoms of mange caused by mites include intensive itching in the affected areas. Hair may be rubbed off the areas, and small lesions and nodules may be noticeable. In some cases the skin may scab, and it generally becomes cracked and dry. The horse may bite and lick at the area if possible. These affected areas may spread across the horse's whole body. Mites may be visible by the naked eye, but a definitive diagnosis may be made by a veterinarian taking a skin scraping to examine microscopically.
Treatment for mites depends on the severity. Basic treatment involves washing the infected areas on the horse with an insecticide shampoo. After thoroughly drying the area, you can apply an antiseptic cream or spray. You may need to administer antibiotics in addition to the topical creams, depending on each case's severity. To stop mites from spreading to other horses, the infected horse should be separated from the others. Use equipment such as grooming tools and tack items only on that particular horse.