ELI5: Explain Like I'm 5

Deciduous hoof capsule

Have you ever seen a horse's foot? Well, it's like a big fingernail covering their toes, but it's called a hoof. Just like our nails grow, a horse's hoof also grows and changes over time.

Now, some horses live in places where the weather gets really cold or really hot, and these extreme temperatures can make their hooves crack, just like our skin can get dry and crack in the winter. But horses are smart! They have a trick to help protect their hooves from getting damaged by the weather.

They have something called a deciduous hoof capsule. "Deciduous" means something that falls off or is shed, and "hoof capsule" means the hard part of the hoof that covers the toes. So, the deciduous hoof capsule is like a little jacket that covers the growing part of the hoof and protects it from cold or hot weather.

As the horse's hoof grows, the old and worn-out part of the deciduous hoof capsule starts to loosen and eventually falls off, kind of like how we shed our skin. Then, a new layer of hoof material will grow and become the new deciduous hoof capsule.

This happens until the horse reaches about two years old, and then their hooves grow a little differently, without the deciduous hoof capsule. But it's a really cool way that horses protect their hooves and keep them safe and healthy!