Applying Insect Repellents

Applying Insect Repellents

If the horse is used to fly control products, he might be willing to stand quietly as you apply the products, either at liberty or held by a loose lead line in-hand.

Photo: The Horse Staff

For many horse owners, applying fly control products to a horse involves nothing more than spritzing on a little spray before turning out or tacking up. But other owners don't have it so easy: The horse shies away from the spritzer bottle, won't tolerate fly products on its face, or breaks out in a rash from the repellents. Regardless of whether your horse is troublesome or trouble-free when it comes to fly control, there are basic do's and don'ts that every horse handler should follow in order to keep a cooperative horse cooperating, to gain the agreeableness of a difficult horse, and to maintain maximum safety for horse and handler.

Begin the fly control program when you start seeing flies in the spring, and continue until the flies are finished for the season. There are a myriad of product types that one can use--sprays, gels, pre-moistened wipes, liquids, ointments, roll-ons, powders, pour-on dips, foams, tags, and strips. It's a matter of personal preference and what you find easiest for your horse.

Powders and dips are not very popular. Powders are messy, can drift into the eyes and nose, and can be shaken or rolled off. Dips are pretty inconvenient to use on a regular basis, at least for standard-sized horses and ponies. Unless you have an equine-sized pool or tub that you can run a horse or a number of horses through, you'll have to mix the dip in buckets of water and pour it on the horse.

Strips that can be braided into the tail are handy for broodmares or other pastured horses that aren't going to be sprayed every day, notes veterinarian Linda Thompson, DVM. "Tags can be braided into the mane, but tend to be fairly heavy for the tail. Usually they are only used on horses that are out all of the time."

By far the most popular are the sprays and dab-ons. Sprays are fast and easy to use on the body, legs, and tail, but are a little tricky to use on the face, where the mist can drift into eyes, ears, or nostrils unless you're very careful and cup your hand around those areas to block the spray. Dab-on types (the gels, ointments, pre-moistened wipes, liquids, roll-ons, and foams) take longer to apply, but are good for using on the head because you can control exactly where they go.

Basic Application

The first step in applying your product of choice is selecting a location in the paddock or pasture that's safe for horse and handler. "Never apply fly control products, especially petroleum-based products, in a confined, non-ventilated area," warns Thompson. "The toxic levels from those can be reached very quickly. Instead, take the horse into a larger, open area. Make sure the area you work in is free from obstacles that could scare or hurt the horse if he gets 'goosey' and backs up suddenly."

If the horse is used to fly control products, he might be willing to stand quietly as you apply the products, either at liberty or held by a loose lead line in-hand or secured to a fence. If the horse is uncooperative about having fly control products applied to its body, you'll need to work on desensitizing the animal. (More on that later.)

Wear plastic gloves in order to keep repellents from getting on your skin. "All fly products are poison," Thompson states. "If it's poisonous to insects, it's somewhat poisonous to humans, as well. Some of those products can be absorbed through the skin or get into small cracks through the skin. You can buy cheap latex exam gloves in boxes of a hundred fairly inexpensively. Or, you can use dishwashing gloves from the grocery store." If you're working with a spray, you might want to wear a mask, especially if you are sensitive to the smell or have respiratory problems. Be sure you work with your back to the wind so the spray is carried away, not toward, you.

Apply the insecticide according to directions to the horse's head, face, neck, body, legs, and tail. "Do not apply the product to the mucocutaneous junctions (the junction of hair and nonhair) such as the lips, mouth, eyes, nostrils, vulva, and penis," Thompson says.

Take special care when working on the face. "People tend to not treat the face because they're worried about the eyes," Thompson says. "But faces are extremely important, because flies and gnats love faces. Flies like the wettish areas around the eyes and gnats like to congregate in the ears, which makes the horses crazy!"

A good way of putting fly control products on the face is with a dishwashing sponge that comes on a wand. "You can soak or spray the sponge with the fly control product, then just wipe it on," Thompson says. "It's cheap, easy, and works great."

Apply the repellent in a half-circle area underneath and around the sides of the eyes, keeping the insecticide about a finger-width away from the eyes. Thompson prefers not to treat the area above the eyes because if the horse sweats, the sweat can carry the repellent into the eyes. Put a light application of repellent outside and inside the ears. Never, ever pour insecticides into the ear: Just gently dab the product onto the inside of the ear itself.

Avoid applying repellents to areas that are going to be underneath the saddle, pad, girth, bridle, or boots. "It's fairly hard on the horse to have the fly control product applied, then tack put over the top with the horse sweating under there," says Thompson. "These items can hold heat and cause an adverse reaction." She advises riders to tack up the horse first, then apply the insecticide. When using sprays, protect the saddle with a sheet. Use a dab-on product to get in the small, exposed areas around the bridle.

Do No Harm

Before applying the insecticide, read label instructions carefully for frequency and amount of application. "Some labels say 'wet the hair,' which doesn't mean soak the horse: The external parts of the hair should be wet but the skin should be dry," says Thompson. "Some products say to apply a 'fine mist,' which is less than wetting the hair. The biggest thing for either is the skin should not be soaked."

Overdosing the horse could cause a severe local skin reaction. "The horse can get itchy hives or oozy bumps," Thompson warns. "They act like they're burning, which they are." Horses that are sensitive to a repellent will respond similarly. Should the horse have a reaction, hose the repellent off as soon as possible.

"Usually a reaction is not a medical emergency," says Thompson, "unless the horse is extremely covered with hives and is having trouble breathing. In that case, it is a medical emergency, and your veterinarian needs to come out right away."

To avoid risk of a reaction, it's wise to do a skin patch test on a lower limb. Just apply a little repellent to a small area, and monitor any skin reactions. If nothing untoward happens within 24 hours, chances are very good that the repellent is not going to cause a reaction on the rest of the body.

Although fly control products can be toxic to horse or handler if used improperly, generally they are safe when used as directed. "These products are formulated to remain on the skin," Thompson says. "The trick gets to be where there are small cracks, punctures, cuts, or little openings on the skin, things that we wouldn't notice on the horse (or ourselves); these small breaks offer an easy avenue for the products to get inside the system. Generally this is not going to be an issue unless the horse is repeatedly dosed with massive amounts of repellents."

Resistance Is Futile

While many horses are perfectly accepting of fly control products, other horses are scared of them, especially the spray types.

"All horses are born neutral to a procedure such as this," explains equine behaviorist Sue M. McDonnell, PhD, Cert. AAB. "This is not a noxious stimulus. It's just a novel stimulus. Whether a horse becomes a problem in this regard is completely dependent on its experience with it."

Handlers can inadvertently convey to the horse that repellents are scary by over-restraining the horse, over-reacting, and yanking the horse if the horse jerks back, or by tensing up and sending signals that something is amiss. Handlers also can confirm to the horse that repellents are an unpleasant experience by getting repellents into the horse's eyes, nostrils, or other sensitive areas.

Desensitizing is the key to overcoming the fears of a horse which has had negative experiences with fly control products. This usually only takes about two or three five-minute sessions, McDonnell says. Generally, the horse is afraid of the sound of the spritzer bottle and/or the smell of the product.

First, apply the product in the middle of a large paddock free from objects where the horse won't get in trouble if he shies away. Don't work in crossties. "If he resists," she says, "he tightens the restraints, so the message he gets is this really is a bad thing!" Holding the horse by the halter or lead shank, begin by applying the product to just a small area on the shoulder or side, not on more sensitive areas like the face or legs. If he dances away, that's okay. "Just stay with him," McDonnell advises. "Don't yell or upgrade the restraint, but safely move around with him. If you don't crack down on the restraint, they aren't going to accelerate their resistance, so just ride that out, and they'll find it's not so bad. Follow immediately with a positive reinforcement. The horse will get the message that a little resistance isn't going to stop this, and that this isn't that bad, after all."

Start out using ordinary warm water, hold the spritzer a few inches back, and spritz at half-second bursts in one area until the horse relaxes, then immediately reward. "Start over again and do this two or three times in the same location," McDonnell says. "Some horses just give right in and let you go right to their legs, their head, their tail. When they accept it in one area go on to the next." This is an especially good exercise for horses which are bothered by the sound of the spritzer. Once the horse is reliably accepting of being spritzed by water, you can introduce the repellent.

For horses which seem resistant to the smell, apply the repellent with a sponge, and get them used to the smell that way, again starting out in small areas and rewarding them when they relax.

McDonnell says it's very important to commit to the desensitization technique. "If you spritz and they jump and you stop spritzing, the horse has learned that if they jump or resist in a minor way, they can control your behavior."

In some cases, horses might remain overly sensitive to having repellents spritzed onto their faces. "We had a 10-year-old mare here who would get a little too spunky about getting sprayed on the head," relates McDonnell. "With her, we said, okay, get her used to spraying everywhere else, but sponge her ears and face. Some people prefer to do that anyway because they want to be sure not to get the repellent in the wrong places.

"You might think because a horse has had a really bad experience with repellents that it would take months to regain their compliance," McDonnell continues. "In reality, once you've gotten over that first session, their progress is often rapid."

Common Mistakes

As simple as it would seem to spritz or sponge on fly repellents, many owners make mistakes that either make the products less effective or create problems for the horse:

  • Applying incorrect amounts. "The biggest mistake is putting too much on," Thompson says. Too much repellent can cause an adverse skin reaction. On the other hand, some people put on too little with the result that the horse receives no protection.
  • Ignoring the tail and face. "A lot of people forget about the tail," says Thompson. "The tail is a wonderful distribution tool because once you've put it on there, it applies itself for a while by its swishing action on the horse's back." Some owners worry about getting repellents into sensitive facial areas. But flies are troublesome about the eyes and ears, so repellents should be carefully applied to the face.
  • Getting repellents into the eyes and ears. This truly teaches the horse to be wary of repellents.
  • Overly restraining the horse. McDonnell says it's okay to let the horse move around a little.
  • Being too tense. Some people expect the horse to act up, so they become tense, yank on the horse's halter or lead, and send signals that something bad is happening, says McDonnell.
  • Using non-equine products. "There are misconceptions that fly spray for dairy cows is about the same as fly spray for horses," Thompson says, "but the skin on a dairy cow is a whole lot thicker than the skin of a horse. Use products that are truly horse products."
  • Mixing or interchanging repellents. "Don't mix different kinds of fly repellents together," warns Thompson. "Using them in combination increases the toxic level." When switching to another repellent, don't apply the second repellent until after the first has worn off or been hosed off.

You can choose between taking a few minutes to apply fly repellents correctly or a few minutes to apply them so sloppily that you've created a rebellious horse. The choice should be a no-brainer.

About the Author

Marcia King

Marcia King is an award-winning freelance writer based in Ohio who specializes in equine, canine, and feline veterinary topics. She's schooled in hunt seat, dressage, and Western pleasure.

Stay on top of the most recent Horse Health news with FREE weekly newsletters from Learn More

Free Newsletters

Sign up for the latest in:

From our partners