What unusual feature does a polydactyl cat have?

A polydactyl cat has extra toes. The condition is called polydactyly, a congenital trait in which a cat is born with more digits than the usual number on one or more paws.

Most cats have 18 toes: five on each front paw and four on each hind paw. Polydactyl cats may have additional digits on their front paws, hind paws, or all four paws. The extra toes can be small and thumb-like, or they can be fully formed and functional. The trait is usually inherited and is commonly associated with changes in a regulatory region involved in limb development.

Polydactyl cats have sometimes been called “Hemingway cats” because writer Ernest Hemingway kept several of them. His former home in Key West, Florida, became famous for its population of polydactyl cats and their descendants.

The condition is usually harmless, but extra claws may grow awkwardly or become caught, so owners may need to check and trim them. Extra toes do not automatically indicate a special breed; polydactyly can occur in many ordinary domestic cats.