Description

Horses are susceptible to several kinds of mange caused by different species of mites. Leg or foot mange is caused by the Chorioptes bovis mite and usually is found below the hocks and knees, although an infected animal may have mange on other areas of the legs and body.

Mites live on the surface of the horse's skin, and their bites produce scabs, crusts, lesions, and hair loss. In some cases, leg mange may resemble greasy heel. The mange gets worse during winter time as the hair or feathers on the horse's legs thicken.

Some horses appear to be allergic to the mites and even a few mites create havoc on these horses. Other horses are asymptomatic and will act as carriers, creating new infestations later when the mites gain access to other horses.

A veterinarian or a veterinary dermatologist with knowledge of equine skin diseases will be able to sample affected areas and assess the skin for the presence and type of mite.

If leg mange is not treated promptly, the skin can become infected with bacteria or ringworm. Mange mites can infest humans, so care should be taken to wash thoroughly after contact with infected animals and to make sure the mites don't transfer to clothing or equipment.

Symptoms

• Intense itching leading to the horse's attempt to nibble at the affected area, stamping of hooves, rubbing against surfaces in the stable or paddock, and strange actions that can resemble "stringhalt" and other afflictions as the horse attempts to fight the intense itch
• Localized sores with crusting and scabbing
• Oatmeal-like scale on the hair where mites feed on the body
• Infected sites with symptoms resembling "greasy heel"
• Swollen limbs

Causes

Leg mange is caused by infestation with Chorioptes bovis mites, a microscopic ectoparasite that feeds on the superficial layers of the skin, particularly on the lower limbs of horses.

Prevention

Taking prompt precautions to eliminate Chorioptes mites at the earliest indication of their presence is the best prevention. Once an infestation is diagnosed, prompt treatment based on the recommendation of a veterinarian is required, with thorough cleansing and disinfecting of all tack, stable and paddock areas, equipment, and anything else that might harbor skin debris or other material where mites might survive for up to two months off the horse.

Treatment

When caught early, leg mange can be treated with an injection of Dectomax, which kills both external and internal parasites. Bathing the affected areas with medicated shampoo and brushing to remove scabs and debris is usually recommended.

When using commercial topical insecticides, a thorough dipping or high-pressure spray is necessary to saturate the skin. Available reports show that Ivermectin may be effective in treatment of mites.

In many cases, a course of antibiotics to curb infection and an anti-inflammatory to manage pain are necessary. In addition, the premises, all tack and equipment, and grooming supplies will need to be cleaned and disinfected with follow-up treatments to prevent future infestations.