Summer Sores, How to Prevent
Drs. Foster & Smith Educational Staff

Simple Ways to Help Protect Your Horse from Summer Sores
Summer brings fun to any horse barn. Unfortunately, summer also brings a barrage of insects and an increase in wounds and injuries as horses play and work around the pasture, riding trail, and at competitions and shows. As such, painful and unsightly summer sores can develop amidst all the fun. However, there are simple ways to help protect your horse from these external skin lesions.

equine summer sores defined
Summer sores are parasite-caused skin lesions. They develop when common house, face, or stable flies deposit stomach worm larvae on abrasions, wounds, or near moist areas of the body like eyes, ears, or genitals. These infections cause extreme skin sensitivity and itching. As a result, horses chew, bite, or scratch at the infected area to help alleviate the pain. This often causes unsightly bleeding. Worse, it also delays the healing process and can result in more involved injuries or secondary infections.

These infections mostly occur during the summer months for a number of reasons. First, summer is when flies, which transmit the larvae, are most active. In addition, warmer weather and higher humidity can prolong the healing of scratches, abrasions, and wounds like proud flesh. However, there have been cases where summer sores have appeared to heal during cooler fall and winter months, only to reappear the next spring or summer. Treatment requires a multi-faceted approach and may vary with severity and location of the lesions. Therefore, it is best handled by your veterinarian. Treatment may include Ivermectin-based dewormers, medications to decrease the itching, and antibiotics for secondary infections.

summer sore prevention
Prevention is the best way to protect your horse from summer sores. Thankfully, summer sore prevention is tied to basic horse husbandry, including deworming, fly control, and wound care:

Ivermectin Paste 1.87%  deworming
Control of stomach worms is the best way to help prevent summer sores. Adult stomach worms thrive in your horse's stomach and release their larvae into the digestive tract, where they are passed in your horse's manure and ingested by fly larvae. The fly larvae matures into an adult and the adult fly then deposits the stomach worm larvae onto your horse's wounds. To help break this cycle, use a strict deworming schedule with at least two yearly treatments of Ivermectin, which kills both stomach worms and their larvae.

 fly control
Endure Fly Repellents by Farnam Since flies serve as the intermediate host of stomach worm larvae, effective fly control is also essential. In addition, even if your horse is on a strict deworming schedule, horses in nearby pastures might not be and the stomach worm larvae they pass could be easily carried to your pasture or barn. To combat flies, set perimeter traps and use topical sprays. Spot-ons or suitable insect-repellent salves can add insect protection to your horse's more sensitive areas, including open wounds. Furthermore, fly masks and sheets can also help protect your horse's eyes, ears, mouth, and other moist body areas. Insect repellent supplements may also help kill fly larvae in your horse's manure.

Matrix 3-Step Wound Care System by Aloe Advantage  wound care
Wounds, cuts, and abrasions are vital entry points for stomach worm larvae. Therefore, wound-free horses may have less chance of developing summer sores. Of course, horses often get wounded. However, immediately cleaning and dressing any skin abrasions, cuts, or wounds helps speed healing. Similarly, a clean horse, including the genital area, may have less chance of being infected by stomach worm larvae, since they also seek moist body areas.