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Do Horse Fly Masks and Fly Boots Work? Which Ones Are Best?

Last updated: February 15, 2024

By: Miles HenryFact Checked

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Horseflies are a common nuisance for horse owners and can be difficult to keep away. These pests are attracted to the horse’s heat and movement and can bite and cause irritation. Two popular non-chemical choices that shield horses from insects are horse fly masks and boots, but are they effective?

Fly boots and masks protect horses’ legs and faces from insects and exposure to the elements. The most reliable brand of equine leg boots is Kensington, and the Cashel Crusader is a perfect fly mask for horses.

Many horse owners choose fly protection products based on brand or price. However, sometimes the most expensive brands are not always the most effective. Here are our picks for the best fly masks and boots.

Picture of a horse wearing a fly mask,

Fly Masks and Fly Boots keep insects off horses without chemicals

Keeping your horse protected from flies and other pests is important. Horsefly boots can help keep your horse’s legs free of bites, while a fly mask keeps the pests off their face, ears, eyes, and nose.

Horseflies are prevalent in all geographical areas where horses are kept, and their bites can be painful besides being pesky. But you might not know that they’re also carriers of harmful diseases, like the West Nile Virus.

Fly masks and fly boots work to protect the face, ears, and legs of horses from various insects without resorting to spraying harmful chemicals. The chemical-free alternative is perfect for those who have an aversion or sensitivity toward sprays.

Fly boots and a mask protect your horse from disease

Horse owners need to be aware of horseflies’ effects on their animals. Not only do they aggravate horses and humans, but they also transmit diseases. In addition, horseflies typically lay eggs in moist areas like pools and water troughs, which makes them hard to get rid of.

For females to produce large amounts of eggs, they need blood. They get blood from biting and drawing it out from animals and people. Diseases are transmitted mechanically from infected to noninfected animals by bloodsucking insects.

Because of the large size of horse flies, coupled with their painful bites and frequent interruptions, they transmit disease extraordinarily efficiently. Some diseases transmitted by horse flies include equine infectious anemia virus, Trypanosoma, and Tularemia — also called rabbit fever or deer fly fever.

Fly boots and masks will stop insects from annoying your horses.

An insect doesn’t have to transmit a disease to harm your horse. Some insects attack horses in swarms and cause severe swelling and skin damage.

The annoyance caused by pests always being on a horse causes fatigue, loss of appetite, weight loss, and stress. In addition, insects make some horses nervous and can affect their performance and training.

Some horses are very sensitive to flies. We had a horse that vigorously stomped its feet when flies were on its legs. His stomping was so bad we feared he would cause severe and permanent leg damage if we didn’t control the insect problem promptly.

We first addressed his legs with fly boots, used fly spray twice a day, and took steps to rid the barn of insects as best we could. These steps settled him down, and he stopped stomping.

Picture of a horse with its legs covered.

Fly boots and masks protect wounds from insects.

Flies are attracted to open wounds. They feed on and deposit larvae in moist areas such as sores, cuts, and the horse’s eyes. Flies often deposit Habronema larvae on open wounds and the horse’s eyes.

Flies’ affinity for open wounds is extremely aggravating to horses and is unsanitary. These pests can introduce harmful bacteria shortly after you’ve spent time and effort cleaning the wound.

A fly mask, boots, or bandage applied quickly after prepping the injured area is the best method to keep flies out of the injury.

Fly masks protect from the sun’s harmful rays.

Hair is the primary protection for most horses; however, some areas, such as the end of the nose and around the eyes, are not well covered. In the summer, horses with pink skin or horses that have their ears and faces clipped are prone to sunburn.

Horses with pink skin are also susceptible to developing skin cancers from overexposure to UV rays. Exposure to UV rays can trigger the development of squamous cell carcinoma tumors.

Squamous cell carcinoma is a tumor that arises from the skin cells of the eyelids, oral cavity, and other areas of a horse’s body exposed to the elements. It’s a severe condition.

The best way to protect your horse’s face from sunburn is to use a fly mask made with UV-protective materials. Be sure to read the manufacturer’s label and always purchase a fly mask with UV protection.

There are zinc-oxide creams available that you can apply to your horse’s face that has UV protection. Sunscreen made for humans can also be used and is safe for horses.

Picture of a horse with a rash caused by mites.

Common equine insects

Flies, gnats, mosquitoes, bots, lice, ticks, and mites are the most common pests that annoy horses. Let’s take a closer look at some of the more common insects you find on horses.

House Fly and Face Fly

House flies, and face flies are very similar; neither bite but are annoying small black flies. The face fly is the more aggravating to animals, and they target the tear ducts of animals’ eyes, their nose or wounds, and cuts. These insects lay eggs in fresh manure and can transmit disease into open sores.

Stable Fly

Stable flies are disease transmitters. They are small gray flies that have a painful bite. And yes, they, too, transmit disease.

Horn fly

Horn flies are the small black flies you see congregated on the lower legs of animals. They are blood-feeding insects and wreak havoc on the livestock industry.

In the United States, hundreds of millions of dollars are spent annually on insecticides to reduce the horn fly population because of the tremendous damage they cause to livestock.

Horse Fly and Deer Fly

Horse flies and deer flies are blood-suckers insects that are serious pests to horses and humans. When they bite, they cause blood to flow and attract more flies and other insects.

Horseflies are large; they range in size from 3/4 to 1 1/4 inches long. A horsefly has clear or solidly colored wings. Deer flies are smaller and have dark bands across the wings; both have brightly colored eyes.

These flies transmit disease, and painful bites from a large amount of them can interfere with the grazing of animals. Horses can injure themselves trying to escape these flies.

Horse flies, and deer flies consume significant amounts of blood. It’s been estimated that a group of horse flies consume a quart of blood in 10 days. These insects carry the fatal equine infectious anemia disease, and this is why it is vital to have current Coggins tests on all your horses.

Black Fly

Black flies are the minuscule groups of flies you see in horses’ ears, on their head, neck, chest, and belly. They feed during the day and typically attack thinly-haired regions of the animal.

They create a great deal of annoyance and itching in an animal. Black fly bites cause bleeding and leave a bloody crust. Attacks by large groups can kill a host animal.


Gnats are significant pests to horses. They aggravate horses congregating around the moist areas of their head but also get into the mane, tail, and chest. Their bite leads to hair loss and causes crusting, similar to the effect of black flies.


Mosquitoes like horse-flies can produce significant blood losses and annoyance, primarily when they attack in large numbers. Their bite causes whelps on horses, similar to humans’ reaction to mosquito bites.

Mosquitoes transmit harmful diseases such as equine infectious anemia, eastern equine encephalitis, West Nile virus, and Venezuelan equine encephalitis.

Bot fly

Botflies lay eggs on horses’ forelimbs, shoulders, and lips during the summer and fall. These aggravating pests are digested into a horse’s stomach and passed in its feces, and then the bot fly matures.

Most of their damage is to the stomach lining and the area where the eggs are laid. Seeing your horse chewing on its legs could be a sign of botfly larvae. Botflies don’t bite but can cause external itching and internal damage to a horse’s stomach lining.


Two types of lice affect horses, biting lice and sucking lice. Biting lice are harder to treat and live off blood. Sucking lice feed on skin tissue and secretions.

Lice are typically found on a horse’s head, neck, mane, and tail during winter and early spring. Sometimes, you can see adult lice moving through the hair; the egg stage attaches to the hair.

Lice are mostly species-specific; however, poultry lice have occasionally affected horses. Horses with lice often rub, bite themselves, stomp, and display extreme annoyance.


In some areas of the United States, ticks are prevalent and attach themselves to horses and suck blood like a vampire. Ticks can cause anemia, transmit Lyme disease, and decrease an animal’s ability to fight infections.

Ticks are most commonly found on a horse’s head, throatlatch and ears, mane, tail, and lower abdomen. Ticks cause skin irritation and introduce bacterial skin infections.

Below is a YouTube video about fly masks that we filmed.

The Best Fly Masks

Cashel Crusader is our favorite fly masks

We suggest the Cashel brand fly masks because it’s durable and doesn’t irritate our horses. We use the long Crusader because it covers more area and has ear coverings.

This style also has sufficient room around the eye holes. Cashel sells several styles; however, the Cashel Crusader horse fly mask is our go-to one.

We’ve reviewed a bunch of fly masks and think the Cashel Crusader is the best. More than 200 customers on Amazon have provided reviews of this mask and rated it 4.6 out of 5 stars.

The other two brands, Kensington and Harrison Howard, make high-quality products, and their fly masks provide sufficient protection and may be a better option for your horses.

Gather as much information as possible, read reviews, talk to your friends, and even try different masks. Here are links to Amazon customer reviews to read what others say about the Cashel Crusader fly masks.

Best Fly Boots

Kensington fly boots are our favorites.

Flies can drive some horses crazy. They cause horses to stomp their feet and fidget so much that they don’t even graze. Fly boots are designed to eliminate the flies on a horse’s legs so they can relax and be much more comfortable.

The main concern when choosing fly boots is safety and durability, especially for turned-out horses. Some fly boots are easy for horses to remove; some slip down, and others rub the hair off your horse’s legs.

We recommend using Kensington fly boots. We haven’t had any issues with them slipping down or causing rub issues. They come in three sizes, so you can order a set that will fit your horse.

Amazon customers rated them 4.6 out of 5 stars. Here is the link to Kensington Fly Boots and their customers’ reviews for you to read:


Can you make your own horsefly spray?

Yes, you can make a good horsefly spray with common ingredients around your house. The two ingredients you must include are vinegar and essential oils. I wrote an article on this topic that includes an effective recipe to make your own spray. Do Homemade Horse Fly Sprays Work? A Tried and True Recipe

Why do horseflies chase me?

Horseflies are attracted to warm, moving objects, so a sweaty human wearing dark clothes is a prime target. You can find out more about what attracts horseflies in this article: Why Do Horseflies Bite, Will They Chase You? 7 Facts.

Do horse blankets help keep horseflies away?

Yes, horse blankets provide a physical barrier between the horse and horseflies, and some blankets even have special features that help to repel insects. They are typically made of lightweight material, brightly colored, and possibly treated with insect repellant. You can read more about horse blankets and sheets in this article: Why some horses wear blankets.

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