DIY Fly Spray Recipes for Horses

Horse wih flies all over his head
Virginie Blanquart / Getty Images

About the time you sigh with relief because winter is finally over, the pestiferous bugs show up, making life miserable for both horses and humans. Flies and biting insects aren't just a nuisance, they can carry some really serious diseases, such as Pigeon Fever, West Nile Virus, and Equine Infectious Anemia. Protecting horses from flying and biting insects can be a challenge. While you can purchase commercial fly sprays, many people prefer to make their concoctions.

Before you start mixing and spraying, though, take some time to clean up your horse's stable and pastures with some natural pest control methods to reduce the number of bugs you're fighting.

Garlic and Vinegar

Many horse owners start repelling insects from the inside out. Garlic is a favorite supplement that's believed to help control flies. A University of Guelph study found that excessive feeding of garlic is harmful to horses, and the debate over whether garlic is safe for horses is ongoing. However, the small amount fed by most people is generally considered safe and may help repel face and body flies.

Cider vinegar is a common ingredient in many homemade fly sprays, and feeding it is popular, too. The vinegar is believed to make your horse less tasty to biting insects. You can add cider vinegar to your horse's feed or in its water, and you can combine it with crushed or powdered garlic if desired.

Essential Oils

Essential oils and herbs are often used in homemade fly repellent preparations. Try using lavender oil, eucalyptus, and citronella oils. All are easily found in pharmacies, grocery stores, and health food stores. Pennyroyal is a common oil used in fly repellents, but it is toxic, so it is not a good choice for horses. One study published in 2020 found that an herbal spray combining various essential oils may be an effective treatment for the management of equine insect bite hypersensitivity.

Water-Based Spray

You can make a simple fly repellent using water or mineral oil and a few other ingredients. These sprays can be particularly effective against faceflies. As you may already know, face flies can make a horse frantic, plus they can carry disease.

  • 1 cup water
  • 2 cups apple cider vinegar
  • 1 cup Avon Skin So Soft bath oil
  • 1 tablespoon citronella oil
  • 1 tablespoon eucalyptus oil

Combine the ingredients in a large spray bottle, and shake well. Spray the repellent onto a cloth, and wipe your horse's face with the cloth. Do not wipe around the top of the horse’s eyes because sweat may cause it to run down into its eyes and may irritate the animal. Also, if there is pink skin on your horse's face, put a little sunscreen on it and allow it to dry before putting the fly repellent on it. Carry a cloth with you to reapply the repellent when needed.

Mineral Oil Recipe

This recipe is an oil-based spray for face flies. Mix the ingredients in a spray bottle, and moisten a cloth with the spray to apply it to your horse's face, as with the water-based spray. However, note that this spray attracts dust, so don't use it before a show. As an alternative, you can mix seven parts of water with one part citronella for a non-oily fly spray. Increase the concentration to four parts water to one part citronella during the worst of the fly season.

  • 2 cups of light mineral oil
  • 1/2 cup lemon juice
  • 2 teaspoon citronella oil
  • 2 teaspoons eucalyptus oil
  • 2 teaspoons lemon dish detergent
  • 1/2 cup glycerine (optional)

Lavender Spray

Mix four parts vodka, grain alcohol, or water to one part lavender oil. This also smells nice and works for a short time. It also works well as a relaxing room or linen spray. The alcohol mixtures dry faster than water while leaving the fragrant oil behind.

Repelling Blackflies

Avon Skin So Soft is often recommended for fly control. You can use it to combat blackflies in the spring. It’s not long-lasting, so it has to be reapplied often. It works on humans, too. Just wipe it on with a cloth.

Don't Try This at Home

WD-40 is sometimes recommended as a fly spray. That's not one of the uses recommended by the manufacturer. This is a petroleum product that is designed to displace water, so it can't be good for a horse's skin. Other crazy concoctions, such as a diesel-oil repellent, are equally unsuitable and potentially harmful to a horse (not to mention smelly!). Dryer sheets are often recommended to repel flies, but they might not be very effective.

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  1. Cox A, Wood K, Coleman G, Stewart AJ, Bertin FR, Owen H, Suen WW, Medina-Torres CE. Essential oil spray reduces clinical signs of insect bite hypersensitivity in horses. Aust Vet J. 2020 Aug;98(8):411-416. doi:10.1111/avj.12963