Though in some parts of the country you may still be experiencing winter-like conditions, the calendar says Spring – warmer weather, sunnier skies….and the return of flies! There are a lot of commercial products that do an excellent job of eliminating flies in an stall or even the whole barn, but those usually contain Permethrin, a pyrethroid (synthetic) insecticide. Permethrin is highly toxic to cats and can kill them.
Another pesticide-related option is to use a feed-through fly system like Simplifly by Farnam. It contains Diflubenzuron, which has not shown any long-term adverse reactions in horses. Still, it is a pesticide that the horse digests and eliminates with manure, but the flies can’t mature.
One non-pesticide way to keep flies off your horse is to simply dress him in the equine version of a “HazMat suit” – a fly mask, preferably with an ears and nose covering, a fly sheet with a belly band, and fly boots. All are made of a lightweight material and have the added benefit of keeping your horse’s coat from becoming sunburned.
A second way that works best in the barn, is to keep a steady airflow moving so the flies don't really have a chance to land on your horse. Most summer weather includes cooling breezes (usually from the North) so open the doors and windows to the breeze.
If your summers are humid with little air movement, you might want to give mother nature an extra hand by using a stall or barn fan. Classic Equine Equipment offers several types that are both SAFE and efficient. Don’t be fooled into using a regular household box fan in your barn – it is not designed to be compatible with barn wiring causing a fire hazard.
Finally, there are predator flies that you can use. While it sounds kind of icky, people have used it successfully to keep their fly population down. Fly Predators by Spalding Labs are tiny, completely bite less and stingless and devour the fly eggs before they can develop in manure. And they never become a pest themselves. They will go virtually unnoticed around your barn, but you may have to replenish them after a few summer months.
No matter what system you use – whether it contains insecticides or not – products can only do part of the job. The most important deterrent to pesky flies is to keep your stable yard as clean as possible. That means picking up the manure regularly in stalls, round pens, turnouts, arenas as well as making sure your manure pile is covered. Finally, eliminating standing water from puddles or water buckets will also help keep away those annoying nighttime visitors – mosquitoes.
Finally, planting certain plants around the barn like lavender or chrysanthemum that are known to be hated by flies can help. As can using essential oils like mint or eucalyptus topically on your horse. I don’t know yet if this truly works, but since cedar is known to repel insects, for the summer I switch from pine to cedar shavings.
If you have any other ideas for repelling flies, please feel free to share them in the Comments.