Last Updated on March 26, 2022 by Allison Price
Horse people are well aware that horses have Chestnuts, but not as many know that Ergots can be found on their legs. They are what they sound like and why do horses have them.
Some consider ergots and chestnuts to be vestiges of Eohippus’ pre-evolutionary foot and leg structure. “Vestigial” refers to something that has lost its purpose in the evolution process.
The Chestnut is the tougher fleshy growth just above the knees of the front legs and below the inside of the hind leg hock of horses. They are sometimes called ‘night eyes’ by some. It was believed that this is how horses saw at night. There were also other theories like the Earth being flat. Some horses’ chestnuts grow quickly so they can be trimmed or peeled to give them a more attractive appearance. Horses can even nibble on their chestnuts and trim them themselves. Because they are flesh-based, there is some sensitivity to the layers close to the horse. So be careful when you groom them. Some breeds of horses do not have any chestnuts. Chestnuts are only on the front legs of donkeys or zebras, which are their equine cousins.
What is an Ergot?
The Ergot, a smaller, pea-sized callousy growth that grows on the undersides of horses’ fetlocks, is even more small. All horses may not have all four. Some breeds have more ergot growth, while others don’t have any. They are more common on horses with feathers. They can also be removed if necessary, and they are more sensitive to horses than the rest. The French word for a roosters spur is ‘argot’.
Now that we are familiar with Ergots and Chestnuts, how do they get there? They are unique to each horse, and can be used for identification. Some horses may use their front chestnuts for scratching and rubbing their faces. It is believed that they are similar to llamas’ scent glands. You can see the difference with your nose! You will notice a strong horsey odour when you get closer to them (with your nose!). A cowboy trick is to place a horse’s chestnut in your pocket. Other horses will be interested in you. The ergot acts as an anchor point for the associated ergot ligament. It attaches to the lower pastern. The ergot is thought to act in the same way as the feathers to direct water away from the heel.
It doesn’t matter if they were there by design or accident, it seems that those odd lumps serve a purpose. Is your horse getting all his chestnuts or ergots? What can you do to keep them happy?