One of the not-so-lovely parts of spring, especially here in the Northwest, is when you saddle up, lift one of your pony's feet to clean it out before your ride, and see that the frog of his foot seems to be turning to that characteristic stinky, black goo that means thrush.

Now, if you go and Google "equine thrush" you'll notice right away that the information you get is contradictory, at best. Some sites will tell you it's an anaerobic bacterial infection, others will tell you it's a "yeast" infection, or a fungal infection, or that it's also called "canker" ("canker" is actually a different condition), or that it's simply caused by a chronically dirty stall.

In point of fact, there's good information here. Thrush isn't life-threatening, or even soundness-threatening, usually. But you don't want to leave it untreated, because it can indeed get much worse than you'd have imagined. It seems likely that thrush is primarily caused by the hoof failing to clean itself properly, whether by improper trimming, chronic lameness, or extended inactivity (which might be where the dirty stall mythology started)—which results in unhealthy bacterial growth.

It's hard to mistake thrush for anything else. The frog or portions of the frog may ooze, appear black, and feel spongy, and your horse's foot stinks like a compost pile. Seriously. Thrush doesn't smell anything like dirty-stall, mud, or other natural things your horse's hooves might quite understandably smell of.

The condition is actually fairly common, and exceedingly treatable. The bacterium F.necrophorum commonly is found, if your vet should happen to do a culture. Essentially, though, treatment is fairly simple. If you can do these fairly simple things, you should start to see improvement within a few days.

Get his feet dry, introduce antiseptic, antibacterial, or astringent liquid to the affected areas, trim away rotting frog so bacteria isn't trapped in folds or pockets. A good balanced hoof trim should keep the toe short enough that the foot can land properly flat, and the heel trimmed short enough that your horse's frog makes contact with the ground. That contact is crucial in terms of circulation in the structure of the entire foot. In the picture of the affected frog, you'll notice the heels are quite contracted, affecting the rest of the area around the frog, thus complicating matters.

Dilute bleach water or tincture of iodine work very nearly as well as much harsher and more expensive remedies, or the many supposed specialty thrush treatments you can spend money on. You can soak a badly-affected hoof in dilute bleach water, then scrub clean. Spray iodine tincture into the crevices around the affected frog area, and then do your best to keep the foot clean and dry, but still exposed to the air.

So to get—and keep—your horse's feet dry during a Northwest spring can be a real challenge.If you don't have a stall to bring him into at night, perhaps you can work out an arrangement with a friend who has a spare stall. At the very least, you'll need to make sure he has somewhere to stand in his pasture or pen that's not pastern-deep in mud. Pea-gravel, hog-fuel, or deep wood-shavings in his run-in shed or favorite pasture corner can make a real difference, though, in terms of your horse's hoof-condition.