Horse Chestnuts and Ergots

Let’s start at the beginning of horse chestnuts and ergots – some of which may, or not be, factual. But it’s kinda fun.

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Chestnuts are sometimes called “night eyes” which is a bit creepy by itself. It’s believed that horses can see well at night because of their chestnuts. I can’t pinpoint when this rumor started, but it’s likely before modern ophthalmology.

Many believe that chestnuts are vestigial toes that have migrated. There’s a bit of conflicting information about this thought. Did four toes become the splint bones and the chestnuts? Maybe? Toes are at least somewhere close to the metacarpus or metatarsus. The metacarpus is the cannon bone in the front legs, and the metatarsus is the cannon bone in the hind leg, and chestnuts are not clearly related to these bones. The splint bones are, but not the chestnuts.

Recent evidence suggests that these extra toes, which started out as five total, actually exist in the incredibly early stages of a foal’s development in the uterus. As the foal grows, the toes actually come together to create a hoof that we know and love. This is called digit reduction – instead of toes becoming other parts of a horse’s anatomy. More science and info on this can be found here.

Do all horses have chestnuts?

Most modern-day horses have chestnuts on all four legs. On the front legs, they are above the knee, and on the hind legs, chestnuts are below the hock. Some horses, namely Icelandic and Caspian ponies may be missing the hind leg chestnuts. Many horse relatives, like the zebra, also miss the hind leg chestnuts.

Some believe they are vestigial scent glands. This theory of chestnuts as scent glands perhaps led to a wive’s tale that you can carry the chestnut peelings of another horse into a paddock, and the horses there will come up to you to investigate, thus making catching easier. Has this worked for anyone?

I personally think that horses know our hands and that anytime we have our hands out, there’s a chance for a snack.

These chestnuts are smaller and more flat. Regular massage and peeling help to keep them this way.

Horse chestnuts and ergots come in all shapes and sizes! These hind-leg chestnuts look like a saxophone.

These chestnuts are bananas.

How do you care for your horse’s chestnuts?

Many of us like to keep them flat and tidy, otherwise, they can be a little lumpy and sometimes really pokey and long. The easiest way to keep them tidy is to peel them when they are wet. After a shampoo bath and rinse may be the best time to peel them.

Or, you can keep them oiled up with baby oil or moisturizer and peel them after they are nice and soft. Some folks use petroleum jelly to do this.

I don’t like the idea of using a blade or razor to remove them. In my hands, this is a recipe for a disaster by either cutting too deep or having a wiggly horse dance into a blade. But the truth is I would probably slice my own finger off handling a blade.

Some farriers can trim up chestnuts for you.

On show day, you can spiff up your horse’s chestnuts with a coat of grooming oil, or do nothing and carry on.

None of this is necessary! Most horses have absolutely normal chestnuts that don’t need to be groomed, altered, or oiled up. Some horses, who may have supernatural powers, grow such wild chestnuts that they need to be trimmed. This is usually necessary when the growth rubs against other legs when sleeping.

What’s “under” a chestnut?

I never ever ever thought about this until I learned that a friend’s horse came in from the pasture with a big fat let. Cause of this? A suddenly missing chestnut. There’s no bleeding, but you can see from the photo below that there is skin-like tissue below the chestnut. There were no witnesses, so one can only imagine how this horse managed to do this.

It did grow back to normal after several weeks!

What about ergots?

These are the weird pokey things on the back of the fetlock. Ergots are of a similar texture to chestnuts, but they seem to be able to grow and grow and grow. It is for this reason that I absolutely despise ergots and find them to be all sorts of annoying and strange.

And who named them ergots? This silly word is a variation of the French word for “rooster spur” which, TBH, is pretty spot on.

It’s a bit more interesting to think about where ergots “came from”. The horse’s living relatives of the order Perissodactyla are the tapir and the rhino. Creatures of the order Perissodactyla are odd-toed ungulates, which means they have hooves made of an odd number of toes.

These creatures also have hoof pads or the remains of a hoof pad. It’s just as it sounds, like a built-in squishy pad that the hoof rests on. The theory has it that the horse’s ergot is the remains of the hoof pad. Sorta cool, right?

Most horses have ergots, some don’t. When I had two horses, I only had four ergots between the two of them. Go figure.

Ergots range in size from little nubs to these kickstands.

How do you care for ergots?

Ergots are also easily removed in the washrack after shampoo and a rinse. Or even just a rinse. Much like chestnuts, you don’t have to do anything with them if you don’t want to!

Very small ergots that don’t extend much and don’t grow much may feel like a callous or some sort of skin funk starting to happen.

Just use your fingernails to peel the outer layers away. Your Farrier might also be able to trim them for you. Again, using a blade might be dangerous for your horse and your hands.

Please don’t twist off the ergots. At the back of the fetlock where the ergot sprouts, there are lots of nerves and soft tissue structures meeting up. Keep it all where it’s supposed to be and don’t twist the ergot.

One more note about ergots. Please don’t let them turn into gigantic kickstands or I will hunt you down and peel them off and then smack you with them. Gently.

If you want more horse myths and mysteries, read this article.

A short video about chestnuts

A short video about ergots

A longer video about horse chestnuts and ergots

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