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Posted: 06/15/2022
Horse shaking head surrounded by annoying flies

The Problem with Horse Flies – and What to Do About Them

Sweet, sweet summertime is here. And when the heat is on, so are the horse flies! These pesky insects can cause quite the problem for humans and horses alike. Whether you’re casually riding, grooming or competing in a stadium event, a 1,000-pound horse’s reaction to a horse fly bite can cause serious injury. Bites can potentially lead to bucking and the spread of bacteria, so it’s important to address them proactively.

Here’s the good news: PBS Animal Health carries the “fly control trifecta” of trusted and best-selling brands that horse owners count on each summer. Absorbine, Farnam and Pyranha brands all offer a lengthy history of quality products – for 130, 75 and 50 years respectively! Don’t let them bother you any longer – learn how to help protect your horses against flies and how these and some other top products can aid in bite treatment.

Horse Fly and Deer Fly

What is a Horse Fly?

A horse fly looks similar to a house fly, but it’s much bigger. These pests are about an inch-long with bright-colored eyes and clear or solid wings on gray or black bodies. They’re often found near the woods (especially if cattle are close), standing water, and other bacteria-heavy areas. They are active on hot, humid days and drawn to dark, fast-moving objects. They like sweat and carbon dioxide, which horses and humans both exhale.

These flies can leave painful bites that irritate the horse’s skin and even lead to infection. While male horse flies feed on nectar, females bite horses and humans, feeding on blood to boost their egg production. They use unique scissor-like mouths to bite exposed human skin, and attack the horse’s withers, legs, chest and neck, mopping the blood up after it pools.

Horse Fly vs. Deer Fly

Deer flies are another type of bloodsucking fly that often get confused with horse flies as both can bite humans and livestock. While they share a similar eye color to horse flies, deer flies are dramatically smaller and have dark lines across their wings. Deer flies live in wetland environments and are active during the same summer months as horse flies. Other flies can bother horses and other livestock, too. The most menacing species includes horse flies, as well as stable flies, houseflies, face flies, horn flies, bot flies, gnats and midges. Each of these are attracted to standing water and other areas with moisture that acts as solid breeding ground.

Are Horse Fly Bites Dangerous?

Absolutely, in fact, horse fly bites pose somewhat of a health risk. Most of us recognize how scary it is to be next to – let alone riding on – a spooked horse. These bites are pretty painful and you just don’t know how these creatures will react to one.

Aside from the sheer physical danger a bitten horse might create, the fly’s saliva may cause an allergic reaction, and the bite area can become infected. Flies also can transmit a variety of diseases like equine infectious anemia (EIA), salmonella, pigeon fever, equine influenza, and more.

How to Treat Horse Fly Bites

These bites create more of a cut instead of a small hole, so know what to look for. Always start by cleaning the bite with water, then flush it with a wound treatment or even an anti-itch ointment. Farnam’s Swat Fly Repellent Ointment is a true barn staple (which you can use on dogs, too). This go-to ointment is a tried and true solution for wounds, abrasions and scratches, while also protecting against biting flies. As time passes, watch for signs of infection. Ongoing itching and swelling may be a sign of an allergy to the fly saliva (and a sign to watch the specific animal for future bites).

How to Protect Your Horses Against Horse Flies

Let’s start with ways to protect your horses in the barn. Flies have trouble flying/landing when fans circulate air, so stabling with fans is a good start. But it won’t matter if the stalls aren’t kept clean of wet bedding and manure – we can’t stress this enough. Keep tight lids on trash cans in the barn, and clean the cans regularly to reduce the aromas that attract horse flies.

As we mentioned, flies flock to sweaty, fast-moving horses (especially darker ones) – so you can protect them outside the barn with a light-colored horse fly sheet or other products that cover sensitive parts of the horse’s body. Take a look at some of the other options PBS Animal Health offers to help protect horses from pesky horse flies.

Top Horse Fly Control Products

From sprays to boots, masks to traps and everything in between, PBS Animal Health has a wide variety of horse fly control products from which to choose.

Horse Fly Spray Products

  • Absorbine’s Ultra Shield EX Horse Insecticide and Repellent was voted Reader’s Choice Fly Spray in The Chronicle of the Horse for 2019, 2020 and 2021! That’s probably because its weatherproof, sweat-resistant formula kills and repels biting and nuisance flies, gnats, ticks and mosquitoes for up to 17 days.
  • Farnam’s Dual Defense Insect Repellent for Horse + Rider is a 2-in-1 solution featuring EquiVeil 360° technology for unbeatable, 12-hour coverage.
  • The Wipe N' Spray Fly Spray for Horses by Pyranha offers a ready-to-use citronella scented spray that protects against flies and is also an excellent grooming aid and coat conditioner.
  • Tri-Tec 14 Horse Fly Spray helps shield horses from horse, house, stable, face, horn and deer flies, gnats, mosquitoes, lice, ticks and deer ticks that may transmit Lyme disease. It’s a water-based formula with sunscreen that provides up to 14 days of fly control.
  • Nature's Defense Horse Fly Spray is an alcohol-free formula with a gentle blend of four essential oils (citronella, clove, mint and thyme). The non-greasy, non-irritating spray can be used on horses, ponies and foals. There’s zero preservatives, additives or artificial colors in this product.
  • Ecovet Fly Repellent is another natural product and it’s made in the U.S. Ecovet’s active ingredients are naturally derived fatty acids – not chemicals – and the repellent is safe for horses and cattle.

Horse Fly Masks and Leggings

Feed-Thru Supplements

  • Farnam’s highly palatable SimpliFly Feed-Thru Fly Control prevents the development of stable and house flies in manure of treated horses. It contains a fly-growth regulator, LarvaStop, that stops immature flies from developing into biting, breeding adults.
  • Another product that works from the inside out is Bug Check Feed Thru Fly Control Supplement. This chemical-free feed supplement for horses, cattle, alpacas, sheep and goats delivers natural insect control and enhances the animal's coat.

Horse Fly Traps

  • The Captivator Fly Trap includes Starbar’s patented formula of feeding attractants plus a fly sex pheromone that flies can't resist. Hang it mid-level along fence lines for best results.
  • Hang or stake this Insecticide-free and odor-free EZ Trap Fly Trap from Starbar. These long-lasting, rain-proof adhesive traps attract more flies with no "fly trap" odor.
  • Starbar also created a Fly Stik Trap that’s great in stables and tack rooms. It’s free of hazardous chemicals and safe for use around animals, kids and food. Instead of poisons, it contains muscalure, a scientific formulation of a naturally secreted fly sex pheromone that doubles its attracting power.

Find Horse Fly Protection with PBS Animal Health

Don’t let horse flies “bite” into your summer fun! Keep those horses healthy, happy and trail-ready with top-quality brands like Absorbine, Farnam, Pyranha and more. See our full lineup of horse fly control products to help protect your horses today.

DISCLAIMER: The information provided in this article, and all other articles by pbsanimalhealth is for informational purposes only. This article may have been prepared from multiple sources at the time it was written and is not intended to be used as a sole source of information in making any purchase or specific product use decision. We recommend you always consult with your attending veterinarian to properly diagnose any health-related condition before initiating any prevention or treatment program. Always read and follow each product’s current label instructions and Warnings before use.

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