Top 21 Best Fly Sprays For Horses That Work in 2023

The best horse fly spray as far as function and staying power is Ecovet. It has a unique formula that is the only one backed by independent research.
It is a natural formula and so far has not been shown to cause resistance in fly populations.
However, there are many other chemical and natural options that are effective at repelling flies in many different price categories.

Fly season is in full swing in many parts of the world. We as horse owners are doing all we can to protect our partners from itchy, irritating, disease-carrying nuisance bugs. Fly spray is one way to keep your horse from being eaten up by flies, gnats, mosquitoes and ticks. But with so many sprays out there, how to choose the spray that works the best?

I’ve done some research into how fly sprays work and which ones still work the best this summer.

In this article, I’ll share what I’ve learned about how fly sprays for horses work, how to identify what pests you’re at war with, and the fly sprays (and other products) that work to protect against them. I’ll begin with the chemical-based commercial fly sprays, but also included are many fly sprays based on natural ingredients which work just as well.

How Fly Sprays Work

Fly sprays can work by repelling or killing flies and other nuisance insects (or ticks). 

Different products have different active ingredients to achieve these goals. 

Synthetic pyrethroids are an active ingredient in many fly sprays that claim to kill flies. These chemicals include permethrin, pyrethrins, prallethrin, and piperonyl butoxide.

Unfortunately these chemicals are very irritating to equine skin and so are used at very low concentrations in fly sprays. 

Often, the concentration needed to kill the target insects is well above the amount actually applied to horses. This leads to the problem of resistance among flies. Each generation (which for a fly is around 7 days) the most resistant flies reproduce. Soon, the fly population in an area is hardly affected at all by chemical-based fly sprays.

Active ingredients that repel insects and ticks include citronella, neem oil, other essential oils, and apple cider vinegar. So far, there is no evidence of resistance developing to these ingredients. They do not kill flies or mosquitoes, but repel them.

A note: If you are tempted to try products labeled for cattle or other livestock, be very careful. Horses are much more sensitive to chemicals than cattle and can be harmed by the harsher chemicals and higher concentrations used in cattle insect repellents.

Know Your Flies (and other pests)

It’s important to know what flies or other pests you have when trying to control them. Many flies and small flying insects look very similar, but are easy to identify by their behavior or your horse’s behavior when they are around.

House Flies

House flies don’t bite, but can be very irritating to a horse’s eyes, nose, wounds or sores. In addition, house flies have a role in spreading Equine Infectious Anemia, along with biting flies like stable flies and horse flies. Horses usually twitch in response to house flies.

Stable Flies

Stable flies, in spite of their name, usually don’t like to come too far inside the barn. They are more likely to be found outside. Unlike house flies, stable flies bite. 

Stable flies often prefer to bite horses’ legs, and horses stomp their feet and shake their heads in response to stable flies biting them.

Deer Flies

Deer flies are similar to stable flies. They are small flies that bite and don’t like to hang out inside the barn.

Horse Flies

Horse flies are much larger than house flies or stable flies. They bite hard enough to draw blood. Horses will run from horse flies and may buck if one lands on them or bites them. Horse flies have very large mouthparts and bite quickly for a large blood meal before flying away. This makes it very hard for them to get a large enough dose of the chemicals used in fly sprays meant to kill. Sprays with ingredients meant to repel may be more effective against these big flies.

Horn Flies

Horn flies bite, like stable flies and deer flies, but these prefer to feed on cattle rather than horses. If your horse lives near a cattle farm, horn flies may be a problem. Otherwise you’re more likely to be dealing with the other small biting fly species.

Deer Ticks (Blacklegged Ticks)

Deer ticks are the most common kind of tick that plagues horses in many parts of North America. These ticks are a nuisance and can carry Lyme Disease.

Bot Flies

Bot flies look a little more like a small wasp or bee with long legs, distinct from the other flies. Adult bot flies are not very bothersome to horses. However, they lay their eggs on horses’ coats to be ingested and complete their life cycle internally as parasites. But since the flies themselves don’t bother horses, it may be more worthwhile to focus on removing the eggs when you see them instead of repelling the flies. 

Gnats or Midges

There are many different kinds of gnats, but in general, they are very small flying insects. Some species bite horses and can be extremely irritating to sensitive skin. They can be found around wet or marshy areas.

Mosquitoes

Mosquitos – small, buzzy, winged insects that plague humans and horses – are the carriers of West Nile Virus. They are most prevalent near stagnant water (even small amounts), as that’s where their larvae mature.

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Best Horse Fly Sprays

Now that you have an idea what pests you have, what sprays will best protect the horses you love from these pests?

Best Commercial Fly Sprays

Chemical Based Fly Sprays

1. Farnam Bronco e

Active Ingredients:

• Prallethrin 0.033%
• Permethrin 0.15%
• Piperonyl Butoxide 0.5%

Labeled as killing stable flies, horn flies, house flies, face flies, horse flies, deer flies, gnats, fleas, ticks (including deer ticks), chiggers, and lice.

2. Farnam Endure

Active ingredients:

• Cypermethrin 0.15%
• Pyrethrins 0.20%
• Piperonyl Butoxide, Technical 1.60%
• Butoxypolypropylene Glycol 5.00%

Labeled as killing and repelling horse flies, house flies, stable flies, face flies, horn flies, deer flies, gnats, mosquitoes, lice, and deer ticks.

3. Absorbine Ultrashield EX

Active ingredients:

• Pyrethrins 0.10%
• Permethrin 0.50%
• Piperonyl Butoxide, Technical 1.00%

Labeled as killing stable flies, horn flies, house flies, face flies, horse flies, deer flies, gnats, mosquitoes, black flies, cluster flies, sciarid flies, midges, pinkies, no-see-ums, deer ticks, lone star ticks, chiggers, American dog ticks, brown dog ticks, gulf coast ticks, fleas, and lice.

4. Manna Pro Optiforce

Active ingredients:

• Cypermethrin 1.00%

Labeled as killing and repelling biting and nuisance flies, gnats, and mosquitoes.

5. Pyranha Wipe N Spray

Active ingredients:

• Pyrethrins 0.10%
• Piperonyl butoxide, technical 1.0%
• butoxypolypropylene glycol 15.0%

Labeled as killing and repelling biting flies, mosquitoes, gnats, and fleas.

6. Pyranha Equine Spray

Active ingredients:

• Pyrethrins 0.25%
• Piperonyl butoxide 2.5%
• Permethrin 0.50%
• Citronella scent

Labeled as killing and repelling stable flies, horse flies, deer flies, house flies, face flies, horn flies, gnats, mosquitoes, bot flies, ticks, fleas, and lice.

7. Manna Pro Pro Force

Active ingredients:

• Permethrin 0.20%
• Pyrethrins 0.10%
• N-Octyl bicycloheptene dicarboximide 0.48%

Labeled as killing more than 70 listed species, including biting and nuisance flies, horse flies, ticks, gnats and mosquitoes.

8. Farnam Mosquito Halt

Active ingredients:

• Permethin 0.20%
• Prallethrin 0.13%
• Piperonyl Butoxide Technical 0.5%
• N-Octyl Bicycloheptene Dicarboximide 2.0% 
• Di-n-propyl Isocinchomeronate 1.0%
• Butoxypolypropylene Glycol 5.0%

Labeled as killing mosquitoes and repelling gnats, face flies, stable flies, house flies, mites, chiggers and lice.

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9. Farnam Tri-Tec 14

Active ingredients:

• Cypermethrin 0.15%
• Pyrethrins 0.2%
• Piperonyl butoxide, technical 1.6%
• Butoxypropylene glycol 5%

Labeled as protecting against biting and nuisance flies, gnats, mosquitoes, deer ticks, and lice.

Natural Fly Spray

In a study conducted by Pennsylvania State University, fly sprays labeled as natural, containing active ingredients other than the synthetic pyrethroids, actually performed better than the chemical fly sprays. This study looked at the behavior of house flies exposed to 7 different fly repellents. All the sprays affected the behavior of the flies, but the natural ones performed at least as well if not better than the chemical based sprays.

One  in particular, Ecovet, stood out as superior to the other 6 tested. It repelled flies more effectively for a longer period of time.

This shows natural fly sprays can perform as well as chemical based fly sprays, without the harsh chemicals. Some of the essential oils included in natural fly sprays can still irritate the skin, but natural products are far less likely to be irritating than the chemical-containing ones.

10. Ecovet

Active ingredients:

• Octanoic acid 5.0%
• Nonanoic acid 5.0%
• Decanoic acid 5.0%

Labeled as repelling flies, gnats, mosquitoes, ticks, lice, and more.

11. Equiderma Horse Spray

Active ingredients:

• Neem leaf
• Neem seed oil
• Citronella
• Lemongrass
• Lemon peel
• Tea tree
• Lavender

Labeled as repelling flies, mosquitoes, ticks, and other biting insects.

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12. SmartPak OutSmart

Active ingredients:

• Geraniol 2.0%
• Peppermint oil 2.0%

Labeled as repelling house flies, stable flies, mosquitoes, and ticks.

13. Whole Horse

Active ingredients:

• Apple Vinegar
• Lemongrass Oil
• Lavender Oil

Labeled as repelling flies, gnats, mosquitoes, and other flying pests.

14. Farnam Nature’s Defense

Active ingredients:

• Citronella oil 0.35%
• Clove oil 0.15%
• Mint oil 0.25%
• Thyme oil 0.25%
• Sodium lauryl sulfate 3.33%

Labelled as repelling horn flies, stable flies, house flies, horse flies, deer flies, mosquitoes, and gnats.

15. Absorbine Ultrashield Green

Active ingredients:

• Geraniol 1.4%
• Clove oil 0.16%
• Citronella oil 0.12%
• Rosemary oil 0.10%
• Lemongrass oil 0.10%
• Cedarwood oil 0.10%
• Thyme oil 0.02%

Labeled as repelling flies, mosquitoes, and ticks.

Best Fly Repellents That Are Not Sprays

Sometimes it’s better to use a product that is not a spray on harder to reach or sensitive areas, like the ears, around the eyes, or near wounds. These products are made to be easily applied to those areas:

16. Farnam Roll-On Endure

Active ingredients:

• Cypermethrin 0.15%
• Pyrethrins 0.20%
• Piperonyl Butoxide, Technical 1.63%
• Di-n-propyl isocinchomeronate 0.5%
• Butoxypolypropylene Glycol 4.85%

Labelled as killing and repelling flies, gnats, ticks, and lice.

This product lasts a long time (a few days at a time) and works well to keep bugs off of specific areas. 

But be careful if your horse has sensitive skin, it is quite irritating and can cause your horse’s skin to swell and welt.

17. Farnam Equi-Spot

Active ingredient:

• Permethrin 45%

Labeled as killing and repelling ticks, flies, gnats, and mosquitoes.

This product is a spot-on product that works for a long time as long as it doesn’t get washed off by rain, bathing, or sweating. It’s meant to only be reapplied every 14 days.

This makes it a really great option for pastured horses, if your horse can handle it. The very high permethrin concentration means it can be extremely irritating to the skin. Watch for signs of discomfort from your horse when you apply it. 

For example, when I put a spot on The Bay, she tries to move away, stomps her feet, shakes her head, or bites at the area where I put it. It’s definitely not for her, unfortunately.

18. Farnam Swat Ointment

Active ingredients:

• Piperonyl butoxide 0.5%
• Pyrethrins 0.2%
• Di-n-propyl isocinchomeronate 1.0%

Labeled as repelling house flies, face flies, stable flies, and horn flies.

Swat is great because it’s a gel that can be applied precisely around wounds, eyes, and other sensitive areas that need protection from flies. It is not as irritating as Roll-on Endure or Equi-Spot. 

Best Homemade Fly Spray Recipes

Now that you know how fly sprays work, and that natural ones can work just as well as chemical based ones, why not mix up your own?

Ingredients included in natural and homemade fly sprays that work:

• Neem oil
• Citronella
• Clove oil
• Thyme oil
• Apple cider vinegar
• Chrysanthemum flower
• Tea tree oil
• Peppermint
• Eucalyptus 
• Lemongrass
• Lavender
• Listerine

Use one of these DIY fly spray recipes, or mix and match ingredients from the above list to create your own!

Use a base of water or vinegar and glycerin, coconut oil, lotion, and/or small amount of dish soap to make sure it mixes well.

20. DIY Fly Spray With Apple Cider Vinegar

1 cup vinegar

1 cup baby oil

¼ cup original Pinesol

1 tablespoon dish soap

1 tablespoon Skin So Soft

1 cup water

21. DIY Fly Spray With Neem Oil

2 cups vinegar

1 cup gentle aloe vera lotion

½ oz pure neem oil

½ oz clove or thyme oil

Have you tried any of these fly sprays or recipes? Which ones worked for you and your horse?

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