Spring really is a beautiful season, unless you're a farrier or horse owner. Mud and horse hair seems to end up everywhere, not to mention stinky hooves. That terrible smell is probably caused by thrush, an anaerobic bacterial infection that eats away at the hoof, usually around the frog area. The good news is that if caught early, it can be easily treated.
An anaerobic bacterial infection means that the infection starts when the hoof isn't getting enough oxygen. Horses shed their frogs twice a year, usually the same time they shed their winter coats, in the spring and again in the fall when their winter coat grows back.
If you or your farrier haven't trimmed, shod or even looked at your horse's feet since last fall, the hoof walls could've grown enough that all the mud has impacted. If the hoof wall grows too long, the frog won't touch the ground, making it impossible for the horse to exfoliate or shed it themselves.
The old dead tissue of the frog will still grow out and separate from the new one growing in, though, leaving gaps in between for thrush to fester and thrive.
Thrush doesn't only show up in the spring. If your horse only gets it in the spring, it's probably related to mud. Others might see it all year round if a horse lives in a stall or small paddock that doesn't get cleaned as often as it probably should. The build up of urine and manure can cause thrush, especially in injured horses on stall rest who aren't able to move around at all.
How to Treat Thrush
As I said earlier, treatment is usually easy. Most cases can be fixed by simply cleaning out your horse's hooves and stall more often. The more you look at your horse's hooves, the more you'll be able to notice any changes that might need some attention and keep their feet healthier.
A clean-ish living area is good for them too. Ok, it's not always easier, but it's cheaper than a gym membership and arguably gives you a better workout... not to mention, potential savings on vet bills.
The frog usually starts to shed at the point and works its way back to the heels, where it flattens and stretches out across, depending on how your horse moves. I'd recommend you call your farrier, but if your farrier can't get out right away, you could gently pull the shedding frog, starting at the point, down to where you get a bit of tension.
Stop there and carefully cut off the loose piece with a sharp knife so nothing can get up inside and fester. You could also cut off the smaller flaps that hang over the heel area, making it easier to clean out that V. Don't rip off more than the frog lets you easily remove. Once oxygen can get to the infected area, thrush usually clears right up.
If you're dealing with a more severe case, there are lots of products on the market that'll help. Any type of antibacterial soap or disinfectant will work. Use a scrub brush so you can get into every crevice.
More often than not, once the horse's hooves are cleaned, trimmed up and have a dry area to live in, thrush will not be an issue.
Image credit: Jean