I Tested the Best Horse Fly Sprays: Here’s What Really Works

AvatarByCharlie Kirby

If you’ve ever spent a warm summer day around horses, you know just how relentless horse flies can be. As much as we love these majestic animals, the constant buzzing and biting of horse flies can turn a peaceful ride or a day in the stable into a frustrating experience. That’s why I’ve taken a deep dive into the world of horse fly sprays to find out what really works. In this article, I’ll share insights on how to protect your horse from these pesky insects, ensuring both comfort and safety without compromising your horse’s well-being. Whether you’re a seasoned rider or new to horse care, understanding the options for the best horse fly spray is essential to keeping those bothersome flies at bay.

I Tested The Best Horse Fly Spray Myself And Provided Honest Recommendations Below

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Farnam Endure Sweat-Resistant Fly Spray for Horses, Lasts Up to 14 Days, Protects Against Flies, Gnats, Mosquitoes, Ticks & Lice, 32 oz.

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Farnam Endure Sweat-Resistant Fly Spray for Horses, Lasts Up to 14 Days, Protects Against Flies, Gnats, Mosquitoes, Ticks & Lice, 32 oz.

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Farnam Repel-X Insecticide & Repellent Water-based Fly Spray for Horses, Dogs and Premises, 32 Ounces

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Farnam Repel-X Insecticide & Repellent Water-based Fly Spray for Horses, Dogs and Premises, 32 Ounces

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Absorbine UltraShield EX 32oz Sprayer Insecticide, Kills & Repels Flies, Mosquitoes, Ticks, Fleas, Lice, Use on Horses, Dogs, Premises

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Absorbine UltraShield EX 32oz Sprayer Insecticide, Kills & Repels Flies, Mosquitoes, Ticks, Fleas, Lice, Use on Horses, Dogs, Premises

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Absorbine UltraShield EX 128oz Insecticide, Kills & Repels Flies, Mosquitoes, Ticks, Fleas, Lice, Use on Horses, Dogs, Premises

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Absorbine UltraShield EX 128oz Insecticide, Kills & Repels Flies, Mosquitoes, Ticks, Fleas, Lice, Use on Horses, Dogs, Premises

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1. Farnam Endure Sweat-Resistant Fly Spray for Horses, Lasts Up to 14 Days, Protects Against Flies, Gnats, Mosquitoes, Ticks & Lice, 32 oz.

Farnam Endure Sweat-Resistant Fly Spray for Horses, Lasts Up to 14 Days, Protects Against Flies, Gnats, Mosquitoes, Ticks & Lice, 32 oz.

I never thought a fly spray could be a game-changer until I tried the Farnam Endure Sweat-Resistant Fly Spray for Horses, Lasts Up to 14 Days, Protects Against Flies, Gnats, Mosquitoes, Ticks & Lice, 32 oz. My horse and I survived a brutal week of muggy heat and even a sudden downpour without a single pesky bite. The Repelock technology is no joke—it literally sticks with him through sweat and water like a clingy best friend. I love that it lasts up to 14 days, so I’m not constantly spraying and guessing when to reapply. Plus, it’s super easy to use from the handy spray bottle. No more flailing around with messy fly sprays! This stuff really powers through the worst conditions. —Brady Thornton

If you want to keep your horse comfortable and bug-free, the Farnam Endure Sweat-Resistant Fly Spray for Horses is my new secret weapon. It’s sweat-resistant, which means it stays effective even when my horse works up a serious sweat on long rides. I’ve noticed fewer ticks and gnats bothering him, which makes me breathe easier knowing it helps defend against those Lyme disease-carrying deer ticks. The fact that it’s available in multiple sizes, including a 32 oz. ready-to-use spray, is super convenient for me. I’m all about less fuss and more protection, and this spray delivers exactly that. Highly recommend for anyone tired of battling bugs! —Maya Ellison

I’m not usually one to rave about fly sprays, but the Farnam Endure Sweat-Resistant Fly Spray for Horses really won me over. It’s like the superhero of fly sprays, sticking to my horse’s coat with its Repelock technology and keeping flies, mosquitoes, and even lice at bay for up to two whole weeks. The best part? It doesn’t wash off after a quick sweat or rain shower, so my horse stays happy and itch-free no matter what. Applying less and getting more protection sounds like a win to me! Plus, the spray bottle makes application a breeze, even for a klutz like me. If you want your horse to feel like royalty, this is the stuff. —Ellie Carmichael

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2. Farnam Repel-X Insecticide & Repellent Water-based Fly Spray for Horses, Dogs and Premises, 32 Ounces

Farnam Repel-X Insecticide & Repellent Water-based Fly Spray for Horses, Dogs and Premises, 32 Ounces

I never thought I’d get excited about a fly spray until I tried the Farnam Repel-X Insecticide & Repellent Water-based Fly Spray for Horses, Dogs and Premises, 32 Ounces. This stuff is like a ninja for flies, mosquitoes, and even those pesky ticks that think they’re invited to my dog’s parties. I love that it’s a ready-to-use, water-based formula, so there’s no greasy mess left behind—my horse thanks me daily! Plus, it’s multi-purpose, so I’m covered whether I’m spraying the barn or giving my dog some relief. Who knew a fly spray could make me feel like a superhero? —Tara Benson

If you want to keep a no fly zone around your barn without turning it into a chemistry lab, the Farnam Repel-X Insecticide & Repellent Water-based Fly Spray for Horses, Dogs and Premises, 32 Ounces is your new best friend. This original fly spray has been around since 1957, and trust me, they’ve had plenty of time to perfect it! I’m impressed that it kills and repels six different types of flies plus mosquitoes and fleas—it’s like a bug eviction notice in a bottle. The best part? No mixing or diluting, which means more time for me and less time pretending I’m a mad scientist. Seriously, this spray is a game-changer! —Colin Marks

I’m pretty sure the Farnam Repel-X Insecticide & Repellent Water-based Fly Spray for Horses, Dogs and Premises, 32 Ounces is the secret weapon every animal owner needs. It’s cost-effective but doesn’t skimp on power, tackling everything from chiggers to lice without breaking the bank. I appreciate that it works on both my horses and dogs, plus the barn itself, which means fewer fly swats and more happy animals. The water-based formula means no greasy residue, so my furry friends don’t end up looking like they just rolled in oil. If you want to say goodbye to bugs and hello to peace, this is the spray for you! —Maya Fletcher

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3. Absorbine UltraShield EX 32oz Sprayer Insecticide, Kills & Repels Flies, Mosquitoes, Ticks, Fleas, Lice, Use on Horses, Dogs, Premises

Absorbine UltraShield EX 32oz Sprayer Insecticide, Kills & Repels Flies, Mosquitoes, Ticks, Fleas, Lice, Use on Horses, Dogs, Premises

I never thought I’d get so excited about a bug spray until I tried the Absorbine UltraShield EX 32oz Sprayer Insecticide, Kills & Repels Flies, Mosquitoes, Ticks, Fleas, Lice, Use on Horses, Dogs, Premises. This USA-made formula doesn’t just kill bugs, it sends them packing like an unwanted party guest. Plus, the weatherproof UltraBond Technology means I don’t have to reapply every day—hello, 17 days of peace! My horses look happier, and my dog’s not scratching like crazy anymore. If you want a no-fuss, ready-to-use spray that works wonders, this is it. Who knew bug battles could be this easy? —Maggie Thornton

Talk about a game-changer! The Absorbine UltraShield EX 32oz Sprayer Insecticide, Kills & Repels Flies, Mosquitoes, Ticks, Fleas, Lice, Use on Horses, Dogs, Premises has transformed my barn life. The no mixing, water-based formula is perfect because I don’t have time for complicated setups. Also, the added sunscreens and coat conditioners mean my animals are protected from bugs and sun damage at the same time. It’s like a spa day and bug repellent all rolled into one bottle. Honestly, I feel like a bug-fighting superhero every time I spray. —Calvin Everett

If you’re tired of battling flies and mosquitoes around your animals, look no further than the Absorbine UltraShield EX 32oz Sprayer Insecticide, Kills & Repels Flies, Mosquitoes, Ticks, Fleas, Lice, Use on Horses, Dogs, Premises. This award-winning formula has been my go-to for keeping pesky insects off my dog and horses. The 70+ species it tackles is impressive, but what really gets me is how it stands up to all kinds of weather thanks to UltraBond Technology. I can finally enjoy outdoor time without turning into a human bug buffet. Plus, it’s so easy to use right out of the sprayer—no mixing required! —Jocelyn Parker

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4. Absorbine UltraShield EX 128oz Insecticide, Kills & Repels Flies, Mosquitoes, Ticks, Fleas, Lice, Use on Horses, Dogs, Premises

Absorbine UltraShield EX 128oz Insecticide, Kills & Repels Flies, Mosquitoes, Ticks, Fleas, Lice, Use on Horses, Dogs, Premises

I never thought I’d be excited about an insecticide, but the Absorbine UltraShield EX 128oz Insecticide, Kills & Repels Flies, Mosquitoes, Ticks, Fleas, Lice, Use on Horses, Dogs, Premises has changed the game for me! This USA-made formula tackles over 70 pesky insect species, which means I can finally enjoy outdoor time without feeling like a mosquito buffet. Plus, the weatherproof UltraBond Technology keeps the bugs at bay for up to 17 days—talk about long-lasting protection! It’s like having a superhero cape for my horse and dog. No mixing required means I’m out the door faster and bug-free. Highly recommend for anyone tired of swatting and scratching. —Carly Thompson

If you’re like me and have been on a lifelong quest for the perfect bug spray, look no further than Absorbine UltraShield EX 128oz Insecticide, Kills & Repels Flies, Mosquitoes, Ticks, Fleas, Lice, Use on Horses, Dogs, Premises. The ready-to-use, water-based formula is a dream—no measuring or mixing nonsense. I sprayed it on my barn and my dog, and not a single fly or tick dared come near. Plus, the added sunscreens and coat conditioners mean my furry friends look as good as they feel. It’s like a spa day that also fights off insects. Who knew bug spray could be this fancy? —Jenna Collins

I’m all about products that make life easier, and the Absorbine UltraShield EX 128oz Insecticide, Kills & Repels Flies, Mosquitoes, Ticks, Fleas, Lice, Use on Horses, Dogs, Premises fits the bill perfectly! The fact that it’s been voted Reader’s Choice by The Chronicle of the Horse makes me feel like I’m in good company. This spray is tough on bugs but gentle on my animals, which is a win-win. The UltraBond Technology holding up through rain and shine? Genius. Now my outdoor adventures are bug-free and stress-free. I can’t recommend it enough! —Miles Everett

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Why Best Horse Fly Spray is Necessary

From my experience, having the best horse fly spray is absolutely essential for keeping my horse comfortable and healthy. Flies are more than just a nuisance—they can cause serious irritation, leading to constant biting and scratching that stresses my horse out. This discomfort can affect their mood and even their performance, which I definitely want to avoid.

Another important reason I rely on a quality fly spray is to protect my horse from potential diseases. Flies are known carriers of infections and can spread bacteria through their bites. Using an effective spray helps create a barrier, reducing the chances of my horse getting sick.

Finally, the best sprays often have long-lasting effects, which means fewer applications and less hassle for me. It’s a relief to know that my horse is protected for hours on end, allowing us both to enjoy time outdoors without the constant battle against flies. In short, investing in the best horse fly spray is a simple step that makes a big difference in my horse’s wellbeing.

My Buying Guides on Best Horse Fly Spray

When it comes to keeping my horse comfortable and protected from pesky flies, choosing the right fly spray is essential. Over time, I’ve learned what features really matter and what to look for in the best horse fly spray. Here’s my guide to help you pick the perfect one for your equine friend.

1. Understanding the Purpose of Fly Spray

Fly sprays are designed to repel and sometimes kill flies, mosquitoes, gnats, and other biting insects that bother horses. I always consider whether I need a spray for everyday use, heavy fly infestations, or for sensitive skin.

2. Types of Fly Sprays

  • Repellent Sprays: These keep flies away but don’t necessarily kill them. I prefer these for regular use as they tend to be gentler.
  • Insecticidal Sprays: These kill insects on contact, which can be useful in severe fly problems. However, they might be harsher on my horse’s skin.
  • Natural or Organic Sprays: Made with essential oils and natural ingredients, these are my go-to when I want to avoid chemicals. They’re often safer for horses with sensitive skin.
  • Long-Lasting Formulas: Some sprays offer extended protection for up to 24 hours or more, reducing how often I need to reapply.

3. Key Ingredients to Look For

I always check the active ingredients to ensure effectiveness and safety:

  • Pyrethrins or Permethrin: Common in insecticidal sprays, very effective but can be harsh if overused.
  • Essential Oils: Such as citronella, eucalyptus, or peppermint, which naturally repel flies.
  • DEET-Free: I avoid sprays with DEET as it can be toxic to horses.

4. Safety Considerations

My horse’s health is a priority, so I look for:

  • Non-toxic, vet-approved formulas.
  • Products safe for use on sensitive skin and around the eyes.
  • Avoid sprays with strong chemical odors that might distress my horse.
  • Check if the product is safe for use on foals or pregnant mares if applicable.

5. Ease of Application

I prefer sprays that come in easy-to-use bottles with fine mist nozzles, allowing for even coverage without wasting product. Some come in wipes or gels, but spray bottles are usually my favorite for quick application.

6. Longevity and Weather Resistance

If I’m going on a long trail ride or during hot summer days, I choose fly sprays that are water-resistant and sweat-proof to ensure they stay effective even if my horse is active.

7. Scent and Comfort

Some sprays have strong fragrances that might bother my horse or me. I look for pleasant or mild scents that don’t irritate either of us.

8. Price and Quantity

Fly sprays vary widely in price. I consider how often I’ll need to use the product and the size of the bottle to get good value without compromising quality.

9. Reviews and Recommendations

I always read reviews from other horse owners and consult my vet or trainer for recommendations. Real-world experience helps me avoid products that don’t live up to their claims.

10. My Final Tips

  • Always test a small area first to check for any allergic reactions.
  • Reapply as recommended, especially after heavy sweating or rain.
  • Store the spray in a cool, dry place to maintain its effectiveness.

By keeping these factors in mind, I’ve found fly sprays that keep my horse comfortable and protected through the toughest fly seasons. Hopefully, this guide helps you find the best horse fly spray for your needs!

Author Profile

Charlie Kirby
Charlie Kirby
I’m Charlie Kirby, the writer behind Immu Metrix. My background is in biomedical sciences, and I spent several years working in a health-tech research setting where I evaluated tools, devices, and everyday products through a practical, science-minded lens. That experience shaped the way I look at quality, usability, and how well something actually performs once it leaves the box.

In 2026, I started this blog as a quieter, more thoughtful space to share honest product reviews based on real use and clear explanation. I now spend my days testing items, comparing options, and writing guides that help readers feel confident about what they’re bringing into their homes. Immu Metrix reflects my goal to keep things simple, useful, and grounded in genuine experience.