Here’s the scoop on four common misconceptions about one of the biggest challenges of summer horsekeeping—keeping bugs at bay.

Myth #1

The more fly spray you apply, the better.

You might think the more fly spray you apply to your horse, the greater the protection against bugs you’ll provide. This is not the case, however. In fact, applying too much fly spray can be harmful. Exposure to excessive amounts of insecticide can cause skin irritation in some horses. Applying too much fly spray is also a waste of money.

To ensure you use the correct amount of fly spray, read the product’s label, then follow the manufacturer’s instructions carefully. Keep in mind that it’s best to apply spray to a clean coat, so  you may want to groom your horse beforehand—he doesn’t have to be show-ready, but you do want to get rid of the worst of the dirt.  When you start spraying, try to be consistent: Uneven coverage may result in flies congregating in areas you missed.

Myth #2 

Even the best fly spray won’t work well in every situation. The ingredients in a fly-control product determine which insect species will be most susceptible to its action. When selecting a fly spray, be sure to read labels and choose a product designed to target the specific pests in your area. For example, one product may be formulated to deter houseflies, while another may be more effective against mosquitoes or gnats.

If you are not sure which winged pests are most active in your area at different times of year, contact your local agricultural extension specialist for guidance.

All fly sprays work the same way.

Myth #3

Fly spray applied to a wet horse won’t be effective.

You may have heard that applying fly spray to a wet horse is pointless. That’s not entirely true. Effectiveness is determined by the concentration of the active ingredient in the formulation—and how much of that product actually ends up on the horse’s coat. If you follow the manufacturer’s instructions, your horse will be protected even if his coat is damp when you apply fly spray.

On the other hand, you don’t want to apply fly spray to a dripping-wet horse because the product will simply be carried off with the excess water. If you bathe or hose off your horse after he’s been sprayed, or if he gets caught in a downpour, you’ll need to re-apply.

Myth #4 

Insecticides and repellents are all you need to protect horses from flies.

Fly sprays are a key part of any insect-control program, but they can’t do the job alone. A better approach is a holistic one,  addressing where insects breed, congregate and feed. This means regularly cleaning feed tubs and areas where food waste accumulates, reducing insect breeding grounds by ensuring proper water drainage, managing vegetation to make it less hospitable to winged pests and using barn fans to keep air moving. Fly parasites—tiny insects that feed on fly larvae—can also help to reduce fly populations on your property.