Horse scabies, commonly called mange, is a condition caused by mites, which are microscopic biting insects that tunnel into a horse's skin. It is highly contagious and can spread through direct or indirect contact. There are different kinds of mange, caused by two types of parasitic mites.
Chorioptic mange is usually seen in draft breeds with feathered fetlocks. The area around the foot and fetlock are the most common areas chorioptic mange affects. Signs include papules (bumps), alopecia (hair loss), thickening of the skin and crusting. If untreated, the condition becomes chronic. A skin scraping viewed under a microscope is necessary for diagnosis.
Psoroptic mange is very rare and centres around thick areas of hair, such as under the mane and forelock, the base of the tail, under the chin and between the hindlegs.
The most severe type of mange is sarcoptic. It causes pruritus -- intense chronic itching--in the anal region, leading to severe biting and scratching, which frequently causes secondary bacterial infections. Papules, lesions, vesicles (serum-filled blisters formed in or beneath the skin), crusting and alopecia are other symptoms. If untreated, sarcoptic mange can lead to loss of appetite, weakness and emaciation.
This demodectic mite lives in the sebaceous glands and hair follicles of the horse. Demodectic mange appears as patchy hair loss and crusting, or as small masses. Lesions are usually on the face, neck, shoulders and forelimbs. It varies from sarcoptic because there is no chronic itching.
Mange is extremely contagious, so mange-affected animals should be quarantined. Topical treatments with anti-ectoparasitics are recommended, however, there are numerous shampoos containing iodine available, which also treat mange. Iodine kills the mites and helps to prevent bacterial infections. Thoroughly scrub the horse down and leave it on the skin for 20 minutes. Oral and injectable treatments include Ivomectrin and Doramectin. Treatment should be repeated within 10 to 14 days to kill the mites, which were still eggs during the first treatment. Soak blankets, brushes and ropes in boiling water and use topical insecticides on saddles.