Preventing Thrush in Horses

Q: I own a 13-year-old Paint gelding and live in an area where it’s been very wet lately. My horse is out in the pasture year round, but he has a run-in for shelter. When I picked his feet today, I noticed that his frog was soft and the part towards the heel was white like the stomach of a dead frog.

He is my first horse and he hasn’t had had any feet problems in the two years I’ve owned him, except for losing shoes. How do I treat this and how can I keep his feet dry? He is currently wearing shoes and bell boots on his front feet. Any help would be appreciated. —Amelia Palmer, via e-mail

A: Due to the rain your horse could be suffering from thrush in the frog, which is a bacterial infection of those tissues, especially over the central sulcus, or cleft. You will notice black malodorous exudates over the area. Thrush is caused by Gram-negative anaerobic (not requiring oxygen to grow) bacteria, and it is often benign, but sometimes the bacteria can invade sensitive tissue, causing prolonged infection and lameness.

Daily cleaning of the dirt/debris/mud can help eliminate trapped moisture and prevent opportunistic bacteria from taking over and creating an infection. This can help not only treat but also prevent thrush. Also provide a clean environment (like a stall) to help your horse’s feet stay dry.

Since the bacteria involved are anaerobic, it is important to open and allow oxygen to get into the affected area. Over-the-counter products are available to treat thrush, and foot soaks can also help your horse fight the bacteria. I personally like to use a hoof care product called Kevin Bacon if the thrush is only in the early stages, but if sensitive tissue is exposed I used a diluted povidone-iodine (Betadine) product such as Xenodine.

If your horse becomes lame after prolonged infection I recommend calling your veterinarian time to provide further evaluation. If the horse lives outside all the time without an available stall, you can manage the case with foot wraps or commercial boots to keep his feet clean and dry.