In the horse, eczema represents practically all forms of skin disease except the parasitic and is seen in the following forms and regions.
1—A form seen in hot weather and variously known as herpes, lichen, summer or saddle mange, and heat pimples. This occurs under the harness where sweating is most profuse, at first as scabby pimples, after which the hair sticks together and falls, leaving scaly bare patches.
2—Then there is a form of scaly eczema which attacks the head, neck, shoulders, elbows, etc. This is a chronic form, with the production of branny scales with thickening of the skin accompanied by itching.
3—A pustular form which attacks chiefly the skin under the mane and tail. The skin is raw and weeping, while the hair mats together in masses and falls and there is a tendency to the chronic scaly form.
4—Eczema attacking the legs is known as mallenders and sallenders if on the back of the knee, or the front of the hock, while if above the heels, in the bend of the pastern it is known as grease. This is characterized by heat, swelling and redness, followed by a vesiculated weeping surface with the formation of a greasy, offensive discharge, scabs and cracks in the skin, followed by loss of hair. Sometimes the irritant secretion gives rise to production of fungus wart-like granulations, known as “grapes” accompanied by great thickening of the skin and swelling of the limbs.
Eczema probably comes from both external and internal causes. Among the external causes are improper grooming and cleansing of the skin, exposure of the animal to constant rain and the use of irritant soap. Grease may be caused by clipping the hair about the fetlock in cold weather and cleaning before the hair has entirely dried.
Among the internal causes are hereditary disposition, improper diet and use of drugs.
Treatment.—First clean the sores, removing all dirt, scabs, etc. For this purpose olive oil is better than water as soap and water are apt to cause further irritation. (If about the tail or mane, clip the hair around the sores). Apply Zinc Ointment at night and morning. Give A.A. three time per day for two days, then I.I. instead of the A.A.
When in the form of “Grease” on the fetlocks, remove the hair from the sores and cleanse them well. In bad cases the application of a bran poultice cleanses them beautifully. Keep the legs as dry as possible. Feed with relaxing or green food, bran mashes, and less stimulating food, especially in the early stage, and give fifteen drops of A.A. Keep the legs as free from dirt as possible. If the horse is not worked let him have exercise daily, and each night and morning after the leg is cleaned apply Zinc Ointment.