Natural Fly Spray for Horses: Benefits and How To Make Homemade Fly Spray

While chemical fly sprays are effective, not everyone wants to handle these strong ingredients or have them around the barn. Thankfully, there are many natural alternatives that are safe and effective. You can even make your own DIY fly spray for horses.  

Why Flies Are a Serious Issue for Horses

Biting flies that affect horses include: 

• House flies 

• Stable flies 

• Horse flies 

• Gnats 

Flies are a nuisance to both horses and humans. Fly bites can cause welts and skin irritation as well as stress and reflexive behavior, such as biting their sides, kicking, and bucking. If a horse stomps away at flies, they can also cause hoof damage. 

Flies can also cause infections, allergic reactions, and disease transmission—horse flies, in particular, can transmit the virus that causes equine infectious anemia.  

Benefits of Using Natural Fly Spray for Horses

If you’re trying to reduce exposure to ​harsh chemicals like permethrin or pyrethrins, a chemical-free fly spray for horses can be an ideal solution.  

These options are safer for sensitive-skinned horses and foals, and can be less hazardous to riders, barn staff, and the environment. 

Strong scents from synthetic fly sprays can be off-putting, while natural horse fly repellents, especially those with essential oils, often have a pleasant or mild scent. 

Common Ingredients in Natural Horse Fly Sprays

Here are some ingredients you may find in a natural horse fly spray. 

Essential Oils Safe for Horses 

• Citronella: This naturally occurring insect repellent works by masking ​​​​scents that are attractive to insects, such as sweat and body odor. 

• Eucalyptus: A 2010 study found Eucalyptus globulus effectively repelled the blood-sucking sandfly. 

• Lavender: Lavandula angustifolia has a soothing floral aroma that is also an insect repellent. 

• Peppermint: Mentha x piperita is a great alternative to chemical scents and repels mosquitos. Peppermint can help soothe insect stings and bites, too. 

• Tea tree: Australian tea tree oil, Melaleuca alternifolia, is antiparasitic and can suppress the ​​​​growth of parasites. However, 100% pure tea tree oil should never be used on animals due to potential toxicity. 

Natural Base Ingredients 

• Apple cider vinegar: This is often used in homemade fly sprays because the scent repels house flies and other biting insects. It also conditions the skin. 

• Witch hazel: This extract has anti-inflammatory, antimicrobial, astringent, and moisturizing properties when applied to skin. 

• ​​​​​Water 

• Aloe vera: Aloe barbadensis is a skin-soothing base ingredient and carrier oil for essential oils. 

Ingredients To Avoid 

• ​​​​​Undiluted essential oils: Animals including horses, dogs, and cats can easily absorb essential oils through their gastrointestinal tract, skin, lungs, and mucous membranes, and higher concentrations of oils can carry a risk of toxicity to horses. 

• Citrus oils in high concentrations: Lemon, orange, and mandarin oils are ​​​​photosensitizing (increase sensitivity to UV light), and should not be used in high concentrations to avoid irritating or burning your horse’s skin. 

How To Make a Homemade Natural Fly Spray for Horses

DIY Fly Spray for Horses 

Courtesy of Doug Thal DVM Dipl. ABVP 

Ingredients: 

• 2 cups white vinegar 

• 1 cup water 

• ​​​1 cup bath oil 

• 1 tablespoon eucalyptus oil 

Combine ingredients and use in a spray bottle. 

Note: Dr. Thal recommends combining a natural fly spray with other fly control methods, including a proper manure management program, for best results. 

Before spraying this all over your horse, apply it to a small patch on your horse’s skin to make sure they don’t have an allergic reaction. 

How Effective Are Natural Fly Sprays?

Natural fly sprays are most effective when you apply them promptly and reapply frequently. Exposure to the sun and oxygen break down the efficacy of natural fly spray ingredients. And these products ​​​​don’t kill insects—they simply deter them from landing on your horse. 

For best results, combine your natural fly spray with the use of a fly mask, a fly sheet, and fly boots.  

Barn management techniques can reduce the fly population as well, such as:  

• Keeping your manure pile far from the barn 

• Frequently removing manure and soiled bedding from stalls, runs, and paddocks 

• Installing overhead fly misters, fly traps, or fly predators 

Safety Tips When Using Natural Fly Spray on Horses

Make sure to test on a small area of your horse before applying to a wider area, and watch for welts or irritation. 

Avoid applying in eyes, nostrils, and open wounds. 

If your horse is especially sensitive, pay close attention to signs of irritation from the fly spray, such as welts, hives, swelling, or itching. 

If you’re unsure if a product is a safe fly spray for horses, consult your veterinarian for advice. 

Natural Fly Spray vs. Commercial Fly Spray

Generally, a synthetic fly spray offers longer-lasting protection because it degrades more slowly. Natural repellents last for a shorter duration and break down faster under UV light and oxygen, requiring more frequent reapplication. 

If you have a heavy fly population, need to protect pastured horses, or have horses outside for an extended period of time, synthetic fly sprays are the best option.  

But for sensitive animals, lighter fly infestations, or a more eco-conscious barn management strategy, natural fly sprays are a great option. Many owners have the best luck with alternating the two products to balance the benefits of each.