Insect bite hypersensitivity (bug bite allergy or IBH) is a common summer problem. Susceptible horses are actually allergic to the insect’s saliva. Horses can have allergic reactions to any biting insect, but the most common are Culicoides (also known as gnats, midges, sand flies, and punkies), black flies, stable flies, horse flies, and mosquitoes.
Symptoms may include hives, itchiness, hair loss, and dermatitis. Diagnosis of IBH can be determined by the time of year the symptoms occur, along with positive allergy test results.
Treatment must first involve avoidance and repelling insects. Routine barn maintenance, such as removing manure and standing water, disrupts insect breeding and decreases their numbers.
For more natural options, consider fly masks, sheets, or wraps. Insect control using insecticides containing at least 0.2% pyrethrin or permethrin is recommended. Always check with your veterinarian first and read the product label carefully before buying and using any pesticides.
Omega-3 fatty acids can also reduce inflammatory reactions. They decrease skin inflammation and promote a healthy coat without the possible side effects of corticosteroids.
Hyposensitization can be used to decrease the symptoms associated with these allergies, by acclimating the horse’s immune system via small, controlled doses of the allergens they’ve reacted to.