Mange is an intensely itchy skin disease caused by tiny spiderlike insects called mites. Mites live on the surface of the skin or in tunnels a few millimetres beneath the skin. Females deposit eggs in burrows or beneath scabs. Eggs hatch in about four days. Mites reach maturity soon thereafter and live only one to two weeks. The whole cycle takes only 15 to 20 days. For horses suffering from chronic mange, the life cycle of the mites just keeps repeating, infecting the horse on a continuous basis. Unless treatment is received, the horse will have no relief. There are several species of mites that affect horses.
Sarcoptic mite is the cause of scabies, burrowing beneath the horse's skin on the head, ears, neck, chest, flank and abdomen. Small red bumps appear around the burrows. As the horse rubs, paws and bites at the skin to relieve the irritation, the resulting trauma produces further skin injury with crusts, weeping serum, loss of hair, and thickening of the skin. Secondary bacterial infection is common and complicates the picture. This type of mite is highly contagious and spread not only by direct contact but also by sharing tack and grooming tools.
Psoroptic mite, also called the tail mite, produces lumps and patches of hair loss over the poll------the area between the ears---mane and tail. They live in colonies on the surface of the skin and spread very quickly. They are not transferable to humans, and can more easily be identified through skin scrapings than sarcoptic mites. This mite has been eradicated from horses in the United States and is rare in horses throughout the world.
Chorioptic mites cause leg or foot mange. It is found below the hocks and knees and especially affects breeds with heavy leg hair, or feathers. These mites live on the surface of the skin and produce scabs, crusts and patches of hair loss. Affected horses spend their time stamping the ground and biting their legs in an attempt to get some relief. Since this mite can survive the extreme temperatures of winter, it is vital that the stables and pastures be treated for this mite, as well as the infected animals. If not, the horse will develop a chronic case of chorioptic mange.
Sarcoptic and psoroptic mites should be treated using a sulphur solution or topical insecticides numerous times, every 12 to 14 days. Topical treatments of organophosphate insecticides are generally effective against chorioptic mites. The skin should be completely saturated and washed, and scabs should be dislodged with a stiff brush. Use of antibacterial medications can be used to treat secondary infections.
Daily grooming is vital in detecting mite infestations early and preventing the spread to other horses. If mites are suspected, contact a veterinarian to discuss a treatment plan. Regularly clean and disinfect stalls, tack and grooming tools to prevent chronic mange.