Abu Shariff's Stables

Equine dermatitis is a catch-all term for inflammatory conditions of the horse's skin that subsequently affect the overall health and sheen of the coat. The skin itself may be red and flaky or, in extreme cases, may ooze fluids

Etiology/pathology

Dermatitis is more of a reaction pattern than a disease classification and may be complicated with other respiratory and/or digestive conditions. Disturbances and/or damage to the dermal cellular production of ground substance glycosaminoglycans— collagen and elastin — negatively impact the skin structure and function. The skin adnexa (pilosebaceous system and the eccrine sweat glands), are complex structures that develop from the epidermis and remain in continuity with it but reside in the dermis. They are highly active structures metabolically and extremely sensitive to toxic and hormonal influences.

Symptoms and diagnosis of dermatitis

Equine symptoms of dermatitis may include superficial skin inflammation characterized histologically by epidermal edema and clinically by pompholyx when acute, poorly marginated redness, spongiosis (intraepidermal edema), oozing, crusting, scaling, pruritus, and lichenification caused by excessive scratching and/or rubbing.

Equine dermatitis may be caused by bacteria, viruses, or allergies/sensitivities to certain substances including insect venom. The primary types of dermatitis are perivascular dermatitis (acral lick dermatitis, flea bite hypersensitivity, sarcoptic mange, atopic dermatitis and other hypersensitivity to insect bites), irritant contact dermatitis, and Pemphigus foliaceus— a relatively rare condition caused by an allergic response to a substance in the horse's own skin.

A horse with severe dermatitis will usually demonstrate scratching, rubbing, chewing and/or biting in the affected region. This is the horse’s attempt to relieve the itch that usually accompanies the condition. Other signs such as urtcaria, papules, scales and crusts are also indicative of dermatitis. Prolonged irritation of the skin is often accompanied by a loss of lustre in the horse's coat.