There are several things that can cause polydactyly ... and trigger a variation resulting in extra digits. If a cat has a dominant polydactyl gene, it will pass it on to its offspring, although ...

Milo's extra toes. His username, @milosixtoes, is a nod to his polydactylism—a condition where cats are born with extra digits. PetMD notes that polydactyl cats are sometimes called "Hemingway ...