Any horse is susceptible to developing thrush if kept in an unclean stall or muddy paddock. Or, if dirt and manure is allowed to build up under the hoof. The condition usually begins in the clefts alongside the frog on the underside of the hoof. Hooves with deep clefts and narrow heels provide an ideal environment for growth, though thrush also happens even in flatter, wider hooves. Horses shod with therapeutic pads are also at risk, as the bacterium can develop between the hoof and pad.
How To Recognize It
Once thrush takes hold, it’s fairly simple to detect. It emits a foul odor and appears as a black pus-like fluid. The black color of thrush will be visible in the clefts against even the gray color of a naturally dark hoof. As the frog is affected, it, too, will become black and spongy. If present in one foot, thrush is often found in all four feet to varying degrees.
Though thrush doesn’t typically cause lameness, it can cause soreness if it migrates deep into the hoof’s sensitive tissues. Allowing thrush to persist that far may cause the horse to flinch as his feet are picked out. He may exhibit lameness, and may even bleed at the site of infection.
How To Treat It
Keep his stall scrupulously clean and dry with plenty of fresh shavings. If he lives in a wet or muddy paddock or pasture, he may need to be moved to a drier, cleaner environment. Make every effort to provide a dry place to stand in a wet paddock or pasture. This may mean building a shelter or a large mound.
To directly battle thrush, remove debris from the hoof with a hoofpick at least twice a day, with attention to the clefts and grooves. Using a clean hoof brush, warm water, and antiseptic, scrub the entire bottom of the hoof, including the sole, frog, and clefts.
Then coat the affected area with an antimicrobial thrush treatment product, readily available at tack stores or online. Following these steps diligently for a week or more should clear up the thrush, and the hoof should regain its healthy appearance. If the condition persists, even with treatment, contact your veterinarian.