Protect Horses From Potomac Horse Fever Through First Frost

Protect Horses From Potomac Horse Fever Through First Frost

When water is warm, the bacterium that causes PHF passes out of the water snails and is picked up by aquatic insects such as damselflies, caddis flies, and mayflies, which then pass it on to horses.

Photo: iStock

Many horse owners don’t think about Potomac horse fever (PHF) until it’s too late. The bacterium that causes this seasonal disease has a better chance of infecting horses during the late spring to early fall in temperate areas. As a horse owner, you should be on the lookout for any signs until after the first hard frost.

“This disease has already affected several horses this season and it does not show signs of stopping until frost sets in, unless you take steps to help protect your horse,” said Hoyt Cheramie, DVM, MS, manager of Merial’s Large Animal Veterinary Services.

Horses can be exposed to this disease in many different areas—PHF has been identified in 43 states. It is always best to be prepared, plan, ahead and contact your veterinarian to determine what actions you can take to prevent PHF.

Vaccinating horses against PHF is one way to help reduce the risk of disease developing.

When water is warm, the bacterium that causes PHF passes out of the water snails and is picked up by aquatic insects such as damselflies, caddis flies, and mayflies. Those carriers then pass the bacteria—which can cause fever, diarrhea, laminitis, and death in horses—to equids that inadvertently consume them.

Horse owners can take measures to reduce the populations of insects that can carry the organism that cause the disease. Good farm management practices include keeping your horse’s food covered, restricting grazing near creeks or other bodies of water, and using repellents to decrease fly and other insect problems in your barn.

Keeping PHF prevention a priority until the first hard frost will decrease the chances of your horse being affected by this seasonal disease.

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