Perhaps the most common genetic anomaly in cats is polydactyly, a condition that results in extra toes. It’s more common to find these toes on the front paws, and a polydactyl cat may have more than just one extra toe, she could have an entire set.
Dr. Margret Casal, associate professor of medical genetics at the University of Pennsylvania’s School of Veterinary Medicine in Philadelphia, has seen many forms of polydactyly in her feline patients. “I’ve seen cats with as many as five extra toes,” she describes. “And I’ve seen cats with paws that look like mittens. There are all kinds of variations.”
Polydactyly can be a dominant genetic trait, so if a cat has it, it’s quite likely that at least some of that cat’s offspring will as well. It’s also unrelated to a cat’s health, so if your cat has extra toes, they’re typically just a fun, quirky feature.
Pet owners with a polydactyl cat should just keep an eye on those extra toes when clipping nails to ensure there aren’t any hidden claws that may become overgrown. They should also be aware that sometimes the extra toes are not attached to any bones. When that is the case, your veterinarian may recommend that they be amputated. “Because they’re not attached, the cat can’t retract his claw and may become stuck or even accidentally tear off the extra appendage,” says Dr. Krista M. Vernaleken, medical director at Bulger Veterinary Hospital in North Andover, Massachusetts.