This is a trimmed chestnut. They grow a material similar to a nail or horse hoof - ergots are similar, but in a different location. When they get big you just peel or clip it off. They can smell a bit strong when you trim them, but hooves smell worse when the farrier comes out!
violetring
joined 1 year ago
It's actually a really interesting question. It's commonly believed that on horses the vestigial remnants of additional toes/hooves/foot structure are the chestnuts and ergots. The first known horse had 3 and 4 hooves per leg! 
Yes! And they're always walking on their middle fingers.
Time Suck with Dan Cummins
Join the Cult of the Curious and learn about a variety of topics including : cults, historic figures, serial killers and more. Some recent sucks have covered Alexander Hamilton, The Kidwelly Sex Cult, The Taiping Rebellion, The Gainesville Ripper, Elvis Presley, and The Dark Truth about Pornhub.
Hail Nimrod, good boy Bojangles!