Trimming Ergots and Chestnuts on Horses Legs

Updated February 27, 2023

Chestnuts are callous growths on the inside of the horse’s legs – just above the knees on the inside front legs and a bit below the hocks of the inside hind legs. Ergots are another callous structure that sits on the palmar aspect or underside of the fetlock joint. They’re both completely harmless natural skin patches that are unique to every horse – like fingerprints.

Why Do Horses Have Chestnuts and Ergots?

Chestnuts are remnants of toes that horses lost during evolution. Equine anatomy books say that chestnuts are versions of foot pads, the cushions on which animals walk.

Foot pads are quite pronounced in some animals, such as bears, and less pronounced in other animals, such as dogs and cats. In horses, the foot pad is incorporated into the hoof as the frog. The chestnuts are described as “vestigial” knee and hock foot pads, meaning the structures have atrophied and become nonfunctional.

Do All Horses Have Chestnuts on Their Legs?

Some horses have chestnuts that remain flush with their skin and hair and don’t seem to grow much. But each chestnut is a different story – they can even vary from leg to leg on the same horse.

Chestnuts may be long and sharp, hard and cracked, or so prominent that they look like overgrown horizontal mountains. While other horses have naturally soft, pliable, and small chestnuts that come off simply by twisting them or lightly currying.

Certain breeds of horses are also known for typically having larger chestnuts, such as Friesians, Belgian Drafts, and Shires. In contrast, some equids have been known to be missing chestnuts on their some or all their four legs - Icelandic horses, zebras, and donkeys.

Many owners don’t love the look of big leg chestnuts and will trim them down before going to a show or competition. Although, lots of people will just ignore them and wait for chestnuts to fall off naturally.

Ergots on Horses Legs

Not all horses have ergots, and some horses won’t have these small, callous prominences on all four legs. They’re typically covered by your horse’s hair and are more commonly found on breeds with feathers or long hairs on their legs.

Just like chestnuts, ergots vary in size and could become an issue if they’re so long that they catch onto things or make it tough to polo wrap. The ergot is an anchoring point for the ergot ligament which is the most superficial of the ligaments on the horse’s lower leg.

Tips for Trimming, Peeling, and Removing Horse Chestnuts

Figuring out how to remove a horse’s chestnuts and ergots can be a different process for each horse. Here are some tips and tricks for trimming down these callously growths:

• Give your horse a bath to soften the chestnut before trying to peel them off.
• Put some petroleum jelly, baby oil, or moisturizing ointment on the chestnuts for a few days to encourage them to soften and eventually come off with less effort on your end.
• Ask your farrier to trim them with their hoof knife or sand them down with their rasp.
• Work within the chestnut’s layers so you don’t go too deep and hurt your horse or “quick” him as you can with dogs when cutting toenails. Don’t trim deeper than skin level.
• Don’t use a kitchen knife or anything too sharp that could accidentally hurt your horse’s legs. Start by using your fingernails instead to gently pick at them.
• Go slowly and be patient to make the experience a positive and comfortable one for your horse.

Many horses might not appreciate having their chestnuts peeled, so pay attention to your horse’s reaction when touching that area and don’t skimp on moisturizing to soften them first. You’ll have to experiment with different strategies to find the one that what works best for trimming your horse’s chestnuts and keeping them under control!

Article originally published February 26, 2008.