How Bad Is Your Horse’s Thrush?

two brown horses and a gray horse stand together outside

Horses seem to always be in a state of movement-- whether they’re running through the field, trotting in an arena, or just walking over to the next spot to graze. It is a part of their physiology to be on their legs and in motion, which is why proper care of their feet and hooves is so important. Horses that do not receive adequate hoof maintenance-- or whose environments are excessively dirty-- are more susceptible to a bacterial or fungal infection known as thrush.

Although it can be caused by lack of foot care, the shape of the hoof or foot, propensity to lameness, and even diet can also contribute to the appearance of a thrush infection. You want to keep your horse happy and healthy, so make sure you have a powerful anti-fungal spray like Fauna Care Silver Spray in your barn. Treatment with a spray such as this will limit your horse’s chances of developing this irritating hoof disorder-- and keep them happily moving about.

In this article, we’re going to examine:

  • What thrush is
  • How to fight the infection-- including ways to prevent it
  • What to do when the infection won’t clear up
horse laying down
Your horse’s hooves provide their own debris clearing process-- when the frog cannot make contact with the ground, problems can develop.

What is Thrush?

Thrush is the name for a bacterial or fungal infection that targets the horse’s hoof-- specifically the frog portion of the foot. It usually spreads to either side of the frog and gets into the grooves that surround it-- known as the sulci.

It usually starts when the bacteria gets inside the epidermis of the frog, allowing it access to the inside. Sometimes with severe thrush in horses, it can penetrate the inner frog, causing pain and even lameness. There is an unpleasant smell and discharge, and a horse owner may even notice blood on their hoof pick. These are all tell-tale signs that your horse has a thrush infection.

However sometimes thrush is difficult to identify, and horses usually exhibit no signs of a problem until the infection has reached the stage where it smells and there is a discharge. Sometimes it is the ferrier that is the first to notice the problem when they are shoeing the horse. Another common way horse owner’s find that their horse has thrush is just by doing their usual hoof picking. The smell is unmistakable, and the dark discharge is obviously due to the inflamed frog.


According to most equine veterinarians, thrush is caused when there is a problem with the frog itself. A healthy frog is broad and able to bear the weight of the horse as it moves-- which stimulates a healthy frog. A horse’s feet naturally have their own debris clearing devices-- and with contact with the ground-- are able to expand and push the dirt out of the grooves of the frogs. Their own daily  movements are usually enough to keep a horse’s hooves clear of thrush.

However, some horses do not have healthy frogs-- instead they are smaller and tend to be shrunken inward. This is often the result of a genetic issue-- but it can also happen because of poor shoeing or over shearing of the hooves. When this occurs, the frog does not have proper contact with the ground-- so it cannot expand and remove debris accordingly. When dirt is allowed to accumulate in the grooves surrounding the frog, this can lead to bacteria and fungal growth.

What about my horse’s environment?

Some people believe that thrush can be caused by a damp or dirty living environment. While a horse should never live in a filthy stall or barn-- and certainly wet conditions are perfect for fungal growth-- this only seems to be a contributing factor. The infection develops in horses who have problems with their frogs-- not because their environment is wet. If a horse with healthy frogs live in a wet environment-- there is little chance of developing thrush. This is why you see thrush develop in horses who live in immaculate conditions-- because there are issues with their frogs or hoof level.

A dirty environment is another issue-- a horse’s stall should be kept clean and the bedding changed daily. This is the best way to prevent excessive moisture build up. Horses that live in dirty environments are also more susceptible to other diseases besides thrush--  every horse owner should give their horse a clean, healthy environment to live in.

horse being shoed
Ferriers are sometimes the first to notice that a horse has a thrush infection.

How Can I Get Rid of the Infection?

If your horse has come down with this infection, your first course of action should be to treat the present infection. However, in order for any treatment to take hold, you’ll need to make sure that the spray gets into all the small cracks and crevices that surround the horse’s frog. You also want to avoid packing too much antifungal or antibacterial product into the hoof as this may damage sensitive tissue. Instead, it is recommend you follow these steps to get rid of a thrush infection:

  • Wrap a cotton swab around the end of your hoof pick.
  • Soak the swab in an antifungal treatment such as Fauna Care
  • Wipe down the sides of the frog with the swab-- making sure to reach around the sides and into any grooves
  • Clean the cleft of the frog and wipe down any other areas that appear to have infection. Keep doing this until your cotton swab comes away clean.

It’s best to keep up with this type of process each day, and hopefully in time you’ll see the infection subside. Your next course of action after the immediate infection is cleared up is to talk to your ferrier about proper shearing. Make sure you try to prevent this from happening again by ensuring that your horse’s frog is making appropriate contact with the ground.

If bad hoof leveling wasn’t to blame for your horse’s thrush, contact your vet and see if there is some kind of abnormality with their frog. This could be due to a genetic problem, a past injury, or even prior lameness. It’s best to get their opinion to make sure you prevent this from happening in the future.

It should go without saying that a horse should live in a clean area, and have their stall mucked out daily. This keeps the chances of encountering bacteria or fungi in the future even smaller. If your horse is susceptible to thrush, consider picking out their hooves daily-- so you can keep tabs on them and make sure no further problems develop. And of course, make sure your horse gets lots of exercise! This is a great way to prevent thrush in the future, and your horse will definitely enjoy it.

horse running

What if My Horse’s Thrush Won’t Clear Up?

If your horse has a severe case of thrush-- or one that seems to keep coming back repeatedly-- move your horse to the driest place that you can. This will help eliminate the anaerobic environment that bacteria and fungi thrive in. Continue to apply an antifungal treatment to the affected areas-- and don’t hesitate to call your vet if you’re unsure what you’re doing is working. Over the counter sprays are a good way to clear up even the worst thrush infection.

Try to stay away from homemade remedies that include harsh ingredients such as bleach, iodine, or hydrogen peroxide. These can irritate the sensitive frog and surrounding areas-- doing more damage than good. Chemicals are harmful to the hooves-- which are made of protein-- as well as to the sensitive soles. Killing the bad tissue surrounding the infection eliminates oxygen and creates an environment ready for infection. This is usually why horse owners who use these products do not see the thrush clear up.

These types of chemicals are also painful to your horse-- and they may begin to associate pain with any type of treatment in the future. This can lead to problems with ferriers or even with daily hoof picking. Save your horse the pain and don’t employ these types of remedies to get rid of their thrush infection.

Once the thrush has begun to disappear, continue the practice of picking your horse’s hooves daily-- to encourage movement and contact with the ground. Again, regular exercise is key for maintaining healthy feet and hoof growth. It is also recommended that your horse sees a ferrier on a regular schedule for shearings and proper shoeings-- which ensures a balanced hoof to support your horse.

No horse owner wants to see their horse develop a case of thrush-- it interferes with their ability to walk and can be painful, sometimes causing lameness. Make sure you have Fauna Care sprays available to help treat-- and prevent-- bacterial or fungal infections. Keep your horse healthy and infection-free-- with no restrictions on their movements!

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