Enteroliths. In the Surgery Room at the Large Animal Veterinary Hospital, enteroliths are removed from horses, zebras and other equines. Enteroliths are Mg-phosphate concretions that develop inside many equines. Enteroliths typically nucleate on a foreign particular (a "nidus") such as a stone or a piece of metal and can grow to sizes as large as a bowling ball!

Stones which grow inside animals (in their bladders/kidneys/colons) aren’t much different from the ones which grow inside the Earth. In fact, the same techniques that geologists use for studying “Earth” stones can be used to study “animal” stones. So the two seemingly unrelated fields of geology and Vet Med come together here at UCD!