Every horse owner knows flies are a pain. What doesn’t get talked about enough is how much damage they can actually do. Flies spread disease, trigger allergic reactions and leave open wounds and sensitive skin at risk all season long.
The good news is that most of it is preventable. Here’s what flies can do to your horse, and how the right fly protection keeps him healthy, comfortable and out of the vet’s office.
Flies Are More Than a Nuisance
It’s easy to think of flies as a comfort issue. A little stomping, a lot of tail swishing. But for horses that spend their summers outside, every bite adds up. Over a full fly season, that steady exposure can turn into real medical problems.
That’s why the best approach is to stay ahead of flies instead of treating the damage after it’s done.
Horse Health Problems Caused by Flies
Insect Bite Hypersensitivity (Sweet Itch)
Insect Bite Hypersensitivity, often called sweet itch, is one of the most common fly-related problems vets see. It’s an allergic reaction to bites, most often from tiny biting midges (no-see-ums). Horses with IBH itch so badly they rub their manes and tails raw, break out in hives and can’t settle.
Once a horse develops it, it tends to come back every year. Treatment usually means antihistamines, steroids and management changes, but keeping bugs off in the first place is easier on your horse and your wallet.
How to help: A Crusader Fly Sheet covers the body, Crusader Leg Guards protect the legs, and a Crusader Fly Mask with Ears keeps biting insects out of the ears and off the face.
Equine Infectious Anemia (EIA)
Equine Infectious Anemia is the virus your vet tests for with a Coggins. There’s no cure, and it spreads through blood, most often carried from horse to horse by large biting flies like horse flies and deer flies.
Cutting down on bites matters most anywhere horses mix: boarding barns, shows, rodeos and trail rides.
Pigeon Fever
Pigeon Fever is caused by the bacteria Corynebacterium pseudotuberculosis. Flies pick it up from an infected horse’s draining wound or abscess and carry it to the next horse. It causes painful abscesses, often on the chest, and can take weeks to clear up.
Like EIA, the risk goes up wherever several horses share space, so reducing fly pressure across the whole herd helps protect everyone.
Summer Sores (Habronemiasis)
Summer sores happen when flies drop parasite larvae onto moist areas like the corners of the eyes, the third eyelid or an open wound. The result is a raw, angry sore that won’t heal and is easy to mistake for proud flesh or a sarcoid.
How to help: A Crusader Fly Mask puts a barrier between flies and the eyes and face, the spots where summer sores show up most.
Sunburn and Skin Cancer
Fly protection does double duty as sun protection. Horses with pink or unpigmented skin, white markings or blue eyes are most at risk for sunburn, and repeated sun damage is linked to squamous cell carcinoma around the eyes and muzzle.
How to help: The Crusader Fly Mask with Nose covers the muzzle, one of the most commonly affected areas, and every Crusader mask blocks up to 70% of UV rays.
Screwworm and Open Wounds
Flies are drawn to any break in the skin, and some do far worse than irritate. The New World screwworm lays eggs in open wounds, and the larvae feed on living tissue. Keeping flies off cuts and scrapes, along with daily wound checks, is your first line of defense.
How to Protect Your Horse from Flies
The best fly protection works in layers. A mask, a sheet and leg guards together cover the face, body and legs, so flies have nowhere to land.
Fly Masks: Start with the Face
The face is where flies cause the most trouble, so start there. The Cashel Crusader Fly Mask blocks up to 70% of UV rays and keeps flies away from the eyes, ears and muzzle. It comes in four styles (Original, Ears, Nose, and Ears and Nose) so you can match the coverage to your horse.
Every Crusader mask has a three-hole cap design that leaves room for the ears and forelock, shaped eye darts that keep mesh off the eyes and lashes, and trimmable sizing with a Hook-and-Loop Extender for a custom fit.
Fly Sheets: Cover the Body
The Cashel Crusader Lightweight Fly Sheet uses breathable mesh to block insects and UV rays without trapping heat, even on the hottest days. A contoured fit helps prevent shoulder rubs, and the extra-wide belly band covers more of the underside, where flies love to bite. You can even hose your horse off with the sheet on to help him cool down.
Leg Guards: Protect the Legs
Legs take the most bites and are the hardest to cover. That’s why so many horses stomp all summer. Cashel Crusader Leg Guards have four hook-and-loop closures that stay put through stomping and movement, so his legs stay covered all day.
Fly Protection for Riding
Flies don’t stay in the pasture when you saddle up. The Cashel Quiet Ride line is made for riding, from full-body Bug Armor Sets to belly guards and neck covers, and it keeps flies off without getting in the way of your horse’s movement or your tack.
Fly Control Around the Barn
Fly gear works best when you cut down on flies at the source too.
- Pick up manure in stalls and paddocks often
- Keep water fresh and clean up standing water
- Store feed in sealed containers
- Check your horse every day for cuts, scrapes and bites, and treat them early
Frequently Asked Questions About Fly Protection for Horses
What diseases do flies spread to horses?
Flies can spread Equine Infectious Anemia (EIA), Pigeon Fever and the parasites that cause summer sores. Biting insects also trigger Insect Bite Hypersensitivity, or sweet itch.
How do I protect my horse from flies?
Use layers. A fly mask protects the face, a fly sheet covers the body and leg guards protect the legs. Pair that with good barn habits like regular manure pickup and daily wound checks.
Do fly masks prevent summer sores?
A fly mask is one of the best ways to help prevent summer sores, because it keeps flies away from the eyes and face where the sores most often start.
Can a fly mask protect my horse from the sun?
Yes. Cashel Crusader Fly Masks block up to 70% of UV rays, and the Crusader Fly Mask with Nose extends that protection to the muzzle for horses with pink skin.
Build Your Horse’s Fly Protection Today
Fly season is going to come. The health problems don’t have to come with it. With the right mask, sheet and leg guards, your horse stays covered from nose to hoof.
