The hot summer months can be uncomfortable for horses, thanks to more than 30 species of bloodletting flies among the millions of insects that land on horses. And they are more than just an annoyance—bloodletting flies and other insects can transmit diseases and illnesses that can be fatal to horses. However, a number of homemade horse insect sprays can be made to relieve horses of annoying insects and flies.
Horse Fly Repellent
Mixing white vinegar and water in a 50/50 mixture with a few drops of dish soap is a cheap and effective way of repelling flies and other insects. If the insects are very bad, use a mixture with more vinegar than water.
Mix 2 cups white vinegar, 1 cup Avon Skin-So-Soft bath oil, 1 cup water and 1 tbsp. eucalyptus oil in a large spray bottle. Spray liberally all over the horse, being careful to keep out of the eyes and mouth.
Alternatively, mix 1 cup vinegar, 1 cup baby oil, 1/4 cup Pine-Sol, 1 tbsp. dish soap, 1 tbsp. Avon Skin-So-Soft and 1 cup water in a large spray bottle. Spray liberally all over the horse. Avoid the eyes and mouth.
If you want to avoid oil dirtying the horse’s coat, mix seven parts water with one part 100 percent pure citronella and spray liberally on the entire body of the horse. If this doesn’t prove effective, you can try a stronger mix of four parts water to one part citronella.
Horse Insect Repellent
Mix 1 oz. 100 percent pure citronella, 2 oz. Avon Skin-So-Soft, 1 cup cider vinegar, and 1 cup water in a large spray bottle. Spray liberally all over horse, keeping clear of the mouth and eyes.
If your horse’s skin is very sensitive, try an internal fly repellent. Mix 1/4 cup apple cider into the horse’s grain or water once a day. The apple cider will raise the blood acid level enough to bother flies and other insects, but it is safe for horses to consume. Results should become apparent within one week.
U.S. Forest Service Bug Spray
Mix 1 cup water, 1 cup Avon Skin-So-Soft, 2 cups vinegar and 1 tbsp. eucalyptus oil in a large spray bottle. Spray over entire body of horse, avoiding the mouth and eyes.
Make a citrus repellent by mixing 2 cups light mineral oil, 1/2 cup lemon juice, 2 tsp. 100 percent pure citronella, 2 tsp. eucalyptus oil and 2 tsp. lemon dish soap in a spray bottle. Shake gently and spray liberally on horse, avoiding the eyes and mouth.
Most of these recipes contain some form of oil, which will make the horse's coat shiny but may also attract dust, dirt and debris. Always consult your vet before using any homemade insect sprays, especially if the insect bites on the horse become infected.