Is Your Horse Drooling? Why It’s Common in the Summer and How to Fix It

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Is Your Horse Drooling? Why It’s Common in the Summer and How to Fix It

With the start of intense summer heat, some owners notice their horses drooling or slobbering. This is not a direct result of the heat, but rather it usually stems from fungus-infected clover in pastures. Fortunately, this condition isn’t serious, and it can be managed with the tips below.

The Link Between Clover, Fungus and Equine Drooling

Spring and early summer rains bring new growth in pastures, and that often includes an increase in clover. Later in the summer, as high humidity, drought, or continuous pasture grazing begin, a plant fungus called Rhizoctonia leguminicola may develop. The fungus produces a soap-like chemical called slaframine, which causes the drooling.

This condition is known as “slaframine poisoning” or “slobbers.” The fungus infects red clover, white clover, alsike clover, and sometimes alfalfa. This excessive slobbering isn’t usually noticed while out at pasture, but it can be very obvious if the horse is standing still to be groomed or tacked up. This is a harmless reaction and does not require veterinary assistance.

Controlling Clover

Some tips for controlling the clover around your horse include:

  • Removing horses from pastures that you know have clover infested with slaframine.
  • Mow pastures until brown spots are no longer present on the leaves.
  • Increase the concentration of grass by applying nitrogen fertilizer in spring and fall.
  • Rotate pastures to allow the grass to remain tall and competitive with the clover.
  • Broadleaf herbicides that are labeled for pasture use can be used to safely remove existing clover plants from pastures.

Most of the time, slobbers is no more than a nuisance to horse owners. Access to plenty of fresh water will prevent dehydration and should always be provided. There is no treatment needed, and after a few weeks the fungus’ growth subsides.

Wellness Care for Your Horse

Twice yearly veterinarian check ups can help prevent disease and keep your horse in top shape. The vets at Carolina Equine Hospital in Browns Summit, NC, offer advice on nutrition, management, husbandry and exercise, as well as vaccination and deworming programs customized to your horse’s life stage and overall health. Learn more about our services by calling us at 336-349-4080, filling out our convenient online form, or sending an email to to see how we can help your horse stay healthy.