Here Comes the Sun, and the bugs!
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Summer Skin Conditions
Summer weather conditions create ideal environments for various dermatological issues in horses. Understanding these conditions enables early recognition and appropriate intervention.
Sunburn represents a significant concern, particularly for horses with unpigmented skin. Pigmentation in hair and skin protects against ultraviolet light penetration, making non-pigmented horses or animals with white-skinned areas prone to sunburn damage. This damage can result in thickening and scaling on the skin surface, known as keratosis, which may sometimes transform into squamous cell carcinoma. Paint and pinto horses, Appaloosas, and cremellos are most susceptible to developing sunburn, which most commonly affects areas around eyes and muzzles, though horses with pale skin over necks and backs can develop sunburn in those areas leading to behavior changes. Sun damage interferes with the immune responses of skin, creating vulnerability for infections like mud fever or rain rot, while pain can cause head shaking or head shyness.
Prevention requires multiple approaches. Fly masks covering ears and most of the muzzle with extended mesh nosepieces provide face, eye, and ear protection, while UV-resistant fly sheets can block up to seventy percent of UV radiation from the horse's back and torso. Zinc oxide cream, such as diaper rash treatment products, blocks UV radiation and has no harmful effects on horse skin, though its sticky texture attracts dirt. It’s been found that using non-scented natural sunscreen, such as tallow based, can help heal and protect this fragile skin (SKY & SOL) without all the sticky residue of diaper rash creams. Keeping sunburn-prone horses out of sun during peak daylight hours between 10 a.m. and 3 p.m. reduces exposure risk.
Rain rot, caused by bacterial infection, thrives in areas where summers are humid. The bacterium Dermatophilus congolensis typically causes infections on the back, where hair takes on a dull appearance, feels waxy to touch, and breaks off easily in chunks. Factors such as prolonged wetting by rain, high humidity, and high temperature increase dermatophilosis occurrence, with the organism living quietly in skin until infection is stimulated by climatic conditions. Most infections subside in two to three weeks with wounds healing without scarring, though onset of dry weather speeds healing.
Treatment requires gentle intervention. Lesions should be gently soaked and scabs removed, with topical antibacterial shampoo treatment often effective when prescribed along with other medications. Successful treatment requires removing the horse from the damp or wet environment that triggered the infection. The condition can spread through contaminated equipment, necessitating careful attention to cleanliness of living areas, tack, blankets, grooming tools, and accessories. The infecting organism can be transmitted to people by direct contact, requiring affected animals be handled with gloves and thorough handwashing.
Scratches or pastern dermatitis develops under similar conditions but affects lower limbs. This infectious dermatitis is usually worse on white legs and consists of large raised scabs that are quite painful to remove. Damp conditions and skin irritation lead to bacterial overgrowth causing redness, flaking, and crusting of skin, typically on legs and pasterns. Management parallels rain rot treatment, focusing on keeping affected areas clean and dry while applying appropriate antimicrobial products. Green clay can be packed into the open sores to help dry out and heal them. Green clay contains iron and magnesium that support tissue repair and immune function. Applied as a topical poultice (FIELD PASTE), it draws out impurities from wounds, cleanses tissue, and may reduce inflammation and pain. The clay provides a cooling, soothing effect while promoting healing by absorbing toxins and excess moisture.
Sweet itch, an allergic response to insect bites, becomes progressively problematic as summer continues. This allergic reaction to bites of Culicoides midges causes intense itching, hair loss, and open sores, especially along mane, tail, and belly line, with hot humid weather increasing insect activity. Management requires comprehensive insect control strategies including fans to deter midges, protective sheets, and medicated shampoos to soothe affected skin.
Preventive care encompasses multiple strategies. Providing shaded turnout during peak sun hours, using UV-protective fly sheets and masks, and ensuring proper grooming to remove sweat and dirt reduces risk. Avoiding over-bathing with harsh shampoos that strip natural oils maintains skin integrity. Daily skin inspections enable early detection of developing problems, allowing prompt intervention before conditions become severe or widespread. Supporting skin health through diet with omega-3 fatty acids, zinc, and vitamin E provides internal nutritional support for external protection.
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As always, these recommendations do not replace the advice of your veterinarian.