Natural Fly Spray for Horses

Sorry, guys, but there’s a reason we have chemical-based pesticides: They work. That said, if we can avoid overusing chemicals on your horse’s skin, we will. We tend to think that a natural-ingredient spray, which doesn’t include chemicals, is a ”healthier” choice for daily use.

Most of the so-called ”natural” fly sprays are primarily formulated with essential oils. It’s along the same lines as strewing bay leaves along your pantry shelf to keep bugs from getting into your cereal. Extracts from some of the same spices that sit on your kitchen shelf (thyme, cloves, rosemary, etc.) are used to deter the flying beasts.

The idea behind natural fly repellents is to create an odor that bugs bugs, not kill them. Lots of fragrant — and odorous — ingredients have been used. An extract from a chrysanthemum flower grown in Africa, pyrethrum, is a top natural repellent. (Pyrethrin is the natural compound in pyrethrum.)

But pyrethrum isn’t always readily available. Instead, many manufacturers use a synthetic form of the pyrethrins called pyrethroids. Permethrin and cypermethrin are two man-made pyrethroids often found in chemical fly sprays for horses. Sprays containing pyrethrins can be considered ”natural,” but ones that contain pyrethroids can’t.

EPA Rules.Because we’re aware that ”natural” doesn’t necessarily mean ”safe,” we decided to see how the Environmental Protection Agency (EPA) weighs in on natural fly sprays. Not suprisingly, the EPA has some specific rules regarding what can go into pesticides. In addition, manufacturers must have their products tested to prove they do what they claim to do with minimal risk to the environment and people doing the spraying. That type of testing is expensive — into six figures — and that can be a budget breaker for smaller companies. Farnam’s Equisect and Espree Aloe’s Herbal Horse Spray are both EPA-registered.

But manufacturers can bypass the testing/EPA registration requirement if the product is made only with ingredients that appear on the EPA’s lists of exempted ingredients. There are two lists, one for active ingredients and one for inactive ingredients. All ingredients must be listed on the label. For example, Miracle Coat’s No-Fly Zone and NaturVet’s Natural Horse Spray include only EPA-exempt ingredients. You can see the complete exempt list at There’s also a long list of exempt inert ingredients, which can be found at

In addition to the EPA’s rules, some states have their own rules regarding the use of pesticides, so you might want to check with your state. You can find contact information for the regulating agency in each state at:

Ingredients.With most fly sprays, chemical or natural, the active ingredients are what kill or repel the bugs. Active ingredients are usually less than 5% of the contents of the bottle. The other about 95% are inactive ingredients, and they, too, should cause no harm to your horse.

If you’ve been using a non-chemical fly spray that works for you, and your horse doesn’t have any adverse reaction to it, you might be fine. But if you want to feel a little more assured about it, using sprays that are registered with the EPA will give you some confidence that the ingredients are safe and effective and the dosage is appropriate.

We’re not saying that only products that are EPA-registered work well or are the best choices. We simply learned that registration means the product has been tested and shown to perform as claimed, which is certainly a good thing, and that the ingredients are of minimal risk to you and your horse when used as directed on the label.

But remember, botanical doesn’t mean benign. Oils from natural herbs and spices can be comfortable for one horse, while cause itching on another. You need to test any new product in a small area first to be sure there is no reaction. Be sure to follow the directions or areas of bug bites could be replaced by areas of allergy bumps.

Bottom Line.Natural’s no good if it doesn’t work. Overall, we’ve found natural sprays are OK for a short time, but they’re not going to replace chemical-based choices.

That said, one place chemical sprays are outdone by naturals is for sensitive-skinned horses. There, the Premier Rehydrant Marigold Scent spray from EQyss is the best choice, and it’s been a Horse Journal favorite for many years and an excellent pick.

Espree Aloe Herbal Horse Spray is an EPA-approved product and a tester favorites in our trials, making it our No. 1 choice. It was also our top choice in May 2005 and June 2007.

Article by Nancy Butler, Horse Journal Contributing Editor.

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