Rock fragnment from Cayman's hoof

As you can sort of see the rock fragment is about one centimeter long.
The sharp end facing to the left was in first, and was the sharpest side of the rock.

It is a piece of gravel, but went I was extracting it, I really thought it was a piece of obsidian. Upon examining the rock I realized it was gravel, much to my disappointment.

I was really hoping the rock fragment was obsidian which would be possible due to the location of the pasture.

I got pretty excited.

Abscess Site on Caymans hoof

The black spot at the tip of the toe is the abscess site.
I pulled the rock out. While trimming the other hoof, I cleaned more rock debris out only to find a second abscess. Both hooves where treated and wrapped.

Caymans feet

Cayman is sound after the wraps where removed.