How to treat thrush effectively, and make sure it never comes back

Does your horse have thrush? Do an image search on Google for it and you'll find it's one of the most common problems horse owners encounter. It is not normal, and can be easily treated, but it can cause your horse to be "not quite right" (compensating for the soreness) or even head-bobbing lame.

Horses are exposed to thrush in the environment all the time. Why does it seem to be a problem for some horses, but not others, even those with the same living conditions? Here are three common causes:

The most common cause is that now or at some point, the horse either had heel pain, or the horse's heels weren't being properly engaged (wedge pads, high heels, imbalances, and long toes can all contribute). Contracted heels (where there is a crack in the middle of the frog) are most at risk, because that crack provides the perfect anaerobic environment for thrush to take hold and thrive. Contracted heels are caused by poor trimming and shoeing practices, or not enough movement of the horse, such as a horse that spends a lot of time in a stall.

Sometimes, a horse can have deep, underlying thrush for years before anyone even notices. The frog can grow over the thrush and trap it in there, allowing it to get very deep and VERY painful. If your horse flinches when you clean out his feet (especially around the frog), there is a good chance that there is thrush present.

The second cause, is metabolic issues. Horses that are sensitive to sugars and starches in their diet seem to be more prone to thrush than other horses. Often, reducing the sugar/starch content of the horse's diet and engaging the horse's heels can resolve this rather quickly.

If a horse's immune system is compromised (from fighting off another infection in the body), thrush can take hold, simply because the body is putting all its resources into fighting the other infection. Don't forget to check for dental issues.

Treating thrush is usually simple:

1. Eliminate the cause (poor hoof care, diet, infection).
2. Remove the necrotic/dead tissue to allow access to all infected areas (remember, the frog can grow over and trap the thrush inside). Enlist the help of a qualified hoof care professional for this part.
3. If there is a deep central sulcus (crack in the middle of the frog), gently push cotton in as deep as it will go with a hoof pick. This is easier if you start pushing it in around the heel bulbs. You may be surprised at how deep the infection is. Be very careful and try not to poke too hard as there may be sensitive tissue exposed, but be sure the cotton reaches the deepest part.
4. Saturate the cotton with your choice of thrush remedy, or soak the horse's feet in an antibiotic solution. Start with the least invasive solution first - ideally, something that does not harm or kill living tissue. Apple cider vinegar and Oxine AH work well. Tea tree oil is a natural antiseptic. The cotton will help draw the treatment deep into the sulcus where it is needed most.
5. Repeat the treatment daily until you see improvement, which is usually within 2-3 days if the treatment is working. Then repeat every other day, and taper it down until healthy frog tissue is visible and the central sulcus will no longer hold cotton.

Treatments that probably won't work:

1. Treating the surface of the frog only (this can harden the outer layer and hold deep thrush in).
2. Treating the thrush without treating the trim, which needs to encourage decontraction of the heels.
3. Using the same treatment continuously even though you see no improvement.
4. Not treating often enough or lack of consistency in treatment.

Thrush can and does cause lameness, and is technically a form of navicular syndrome (heel pain). It is often overlooked and can sneak in when you aren't expecting it. Horses can be very stoic and will often not let you know they are hurting until it gets bad enough that they can't hide it anymore. Check your horse's feet and farrier/trimmer work regularly. A healthy hoof with wide, firm frogs is very unlikely to harbor thrush. Oxygen is thrush's worst enemy.

Feel free to post comments below with your favorite thrush remedies or share your experiences. Thanks for reading!

Rebecca Wyatt
Nature's Path Hoof Care