Horses suffering from hypersensitivity reaction may require treatment by a veterinarian. Horn flies are small, biting flies associated with cattle, but are frequently found feeding on the abdominal midlines of horses, particularly those pastured near cattle. Both male and female horn flies are blood feeders and take 20 to 30 meals per day. Repeated bites cause crusty, ulcerated lesions. Using corticosteroid-antibiotic creams may also help minimize inflammation.
Stable flies attack horses' legs and abdomens, and bites result in nodules and crusty lesions.
Both house flies and face flies feed on secretions around the horse's eyes and cause considerable annoyance. Applying repellents to the back and neck can help control house and face flies. Face masks also help reduce eye irritation. Mosquitoes are the most prevalent type of blood-sucking insect. Their most active feeding period is the first two hours after sunset, particularly in warm, moist weather.