Mosquitoes are more than just annoying---these biting insects can carry viruses that cause a number of harmful diseases, including western and eastern equine encephalitis. Vaccinating your horse is the single best way to protect him, but you'll want to take other measures to reduce mosquito populations around your barn:
Eliminate standing water to reduce their breeding grounds. Turn over buckets, wheelbarrows and other tools that can collect rainwater, and fill in potholes where water accumulates. Even dripping faucets can provide enough water for mosquitoes to lay eggs. Make sure your gutters and drainage ditches are unclogged and flowing freely, and change outside water bowls for pets daily.
Encourage natural predators to take up residence on your farm. Birds, bats, fish, dragonflies, frogs and a host of other predators eat mosquito eggs, larvae and adults. Keep ponds and other natural waterways healthy and clean, and plant shrubs and trees that will offer food and shelter to beneficial wildlife. Your local extension agent can guide you on the best choices to make in your region.
Bring horses in from turnout during hours when exposure to biting insects peaks. Most species of mosquitoes are more likely to bite at dawn and dusk. You can also outfit horses with masks with ear covers, fly sheets and other protective gear and use fly sprays labeled to repel mosquitoes.
Set up stall fans. Mosquitoes find their hosts by detecting heat and carbon dioxide, and they are weak flyers who prefer still air. Setting up fans in your barn addresses both issues, first by quickly dispersing the heat and carbon dioxide horses respire, and also by creating breezes that discourage the insects from flying.
This article first appeared in EQUUS issue #431.