Thrush and your Horse’s Hooves
What is thrush?
Almost all horse owners will have a horse with thrush at some time, and it will probably happen quite often. Thrush is one of the most common and persistent afflictions that horses can get, but thankfully it almost always causes few problems, and it is easy to treat. That said, the old adage ‘no foot, no horse’ holds true, and injuries or disease to the hoof should always be taken seriously.

Thrush is a bacterial infection. It’s often mistaken for a fungal infection, but to be able to treat it effectively it’s important to recognize that there is a bacteria - fusobacterium necrophorum - at the cause. This bacteria most commonly infects the softest parts of the hoof, usually the frog, but can affect the sole and heel as well.

Symptoms of thrush
You’ll probably first recognize thrush by its smell. Horse’s feet seldom smell of roses, but thrush has a particularly foul and acid smell. Next, you may see that the affected parts of the sole or frog look black, and have a waxy feel to them. If you gently scratch that black waxy substance with a hoof pick, it may come off, leaving a bright white or light gray area underneath.

What causes thrush?
The bacteria that causes thrush thrives in wet conditions, and that’s what usually leads to thrush in the hoof. Horses that spend long hours standing in mud, puddles, or damp bedding are prime candidates for thrush. Some horses are more prone to thrush than others, and can even get thrush in fairly dry conditions. Usually these are horses that have deep clefts in the foot, such as either side of the frog or between the bulbs of the heel. Moisture can get trapped in these clefts, and that may be enough for thrush to take hold.

What’s the worst that can happen?
Usually horses with thrush won’t be lame, as thrush normally grows on the outside of the sole or frog. However, in severe cases, such as those left untreated for long periods, or where the thrush is growing deep in the clefts of the heel or frog, it can get into the more sensitive tissue inside the hoof. In these cases, the horse will likely experience pain and be lame, and need more aggressive - and immediate - treatment. Thankfully, thrush is usually spotted quickly and is fairly easy to treat. In very severe cases, the affected areas may bleed. If this happens, you need immediate veterinary attention, as infections inside of the hoof can be very serious, and very painful.

Treatment
For mild cases of thrush, there are several commercial products that will kill the bacteria. You can get many of these without a prescription, and you simply paint or dab them on the affected areas. Before applying any treatments, you should pick out the horse’s feet, and then scrub the frog and sole clean with an antibacterial or antiseptic scrub, such as an iodine surgical scrub. Once the area is clean, you can either apply the topical commercial treatment, or pack the area with cotton pads soaked in iodine or another commercial remedy.

You will also need to evaluate the conditions your horse is living in. Are you maintaining your horse’s paddocks and stalls properly, ensuring he isn’t standing in waste or damp bedding? Do your paddocks or pasture provide dry, comfortable places for your horse to stand, or is he often in mud, puddles, or very wet grass? You will need to pay particular attention to your horse’s feet, picking them out more often (at least twice a day). With persistent or recurring cases of thrush, your weekly grooming routine should include gently scrubbing the soles and heels with a surgical scrub or antiseptic soap

For more severe cases, where the horse is lame and there is a risk that thrush has invaded the interior of the hoof, you will need veterinary treatment. If you draw blood when picking out the feet of an affected horse, you will definitely need the assistance of a vet. Your vet will likely prescribe a combination of treatments, including topical antibacterial applications and a course of injectable or feed-based antibiotics. In very severe cases, your vet and your farrier may have to work together to remove badly affected sections of the frog, sole, or heel, and the horse may needs several months to heal before being sound again.

Prevention of thrush
A good, daily hoof care routine is the first step to preventing thrush. Picking out your horse’s hooves at least daily, and thoroughly brushing out the frog and heels will not only help prevent thrush taking hold, it will make sure if your horse does get thrush, you spot it right away. Ensure your horse’s feet are trimmed at least every six weeks to prevent deep soles, which trap the moisture that thrush needs. Next, make sure your horse always has a clean, dry place to stand where he can be comfortable. This is especially important if your horse is stalled, has a run-in shelter, or stands for long periods to eat hay. Wherever your horse spends most of his day needs to be kept clean and dry. As with any disease your horse may get, prevention is better than cure!

Back