Mosquitoes are both a nuisance and a potential health threat to your horse. Weather conditions play a role in mosquito breeding, which explains why some years seem worse than others. You can’t control the weather, but you can take measures to protect your horse. In addition, make sure her vaccinations are current for illnesses mosquitoes transmit; requirements can change when mosquitoes are particularly bad.
Barns and Stalls
Fully enclosed barns and stalls are not healthy for your horse because of the dust and lack of air circulation, especially if your horse has a respiratory condition. If possible, though, put screens on outside windows, and install fans in the aisle and in the stalls to discourage mosquitoes from landing and feeding on your horse. Bring your horse inside at dusk, when mosquitoes are most active, and keep him in through the night during the most active mosquito months in your state.
Fly sheets, boots and masks protect your horse from mosquitoes, so use as much as he'll tolerate and as are suitable for his turn-out conditions—if he’s in a pasture with a lot of trees or other horses who like to rip off clothing, you may go through a lot during the season. Get flymasks with ear coverings for additional protection; you can also get ones with longer noses to more fully protect your horse’s face. The material is a light mesh so it’s as if your horse is wearing a lightweight screen. It gives the added benefit of providing protection from the sun so your horse’s coat won’t fade and his skin won’t burn.
Moisture and Water
The best way to protect your horse from mosquitoes is to make his living area as inhospitable as possible to the insects. Cut and clear tall grass so the ground can drain more efficiently and so mosquitoes can't hide in the grass, especially at drain pipes and culverts. Be sure to fix any leaky pipes or faucets. Empty, turn over or remove any containers that can hold standing water; clean out his water troughs at least once a week. Be sure you drain any old tires laying around. Empty and change water in birdbaths and plant pots, and if you have a swimming pool make sure it’s properly maintained. If you have a kiddie pool either change water weekly or store the pool upright when it’s raining. Don’t forget to cover your trash containers, or poke holes in the bottoms so the water will drain. Even tree stumps can collect water and offer a breeding ground, so fill them with sand or cement.
You can spray the barn, the surrounding environment and your horse with pesticides to deter mosquitoes. Automatic spraying systems work on many flying insects, including mosquitoes. Look for a pyrethoid-based insecticide. You can also use roll-on and spot topical applications for your horse, which are convenient for the face and around the ears. Many of them last longer than sprays. You’ll get more effective control if you use chemicals in combination with other control measures.
- Brevard County: Brevard County Mosquito Control Horse Owners
- University of Florida Institute of Food and Agricultural Services: Protecting Florida Horses from Mosquitoes [PDF]
- University of Kentucky College of Agriculture Cooperative Extension Service: Insect Control for Horses, Horse Barns and Stables—2013
- David De Lossy/Photodisc/Getty Images