If your vet has informed you that your new feline is a polydactyl kitten or if you are considering whether to adopt one, there is nothing to worry about. Polydactyly is not a defect, but is simply a genetic trait that causes an extra toe or toes on your kitten.
Most cats have 18 toes, four on each back paw and five on each front paw, but a polydactyl kitten can have 19 or more. A polydactyl kitten's extra toes can be on any foot. Some have one or more extra toes on one paw, while others have extra toes on more than one paw. Most polydactyl kittens' extra toes are on their front paws, but some have extras on their hind paws or on all four paws. Polydactyly can occur in any breed of cat, and it is widely seen in certain breeds, such as Maine coons.
Polydactyly is a dominant genetic trait. Cats with extra toes generally pass this trait onto about half of their kittens. The specific gene involved is one called Sonic Hedgehog, which works to control the proper growth of fingers and toes in all mammals. The polydactyly mutation is not actually in the Sonic Hedgehog gene itself, though. Instead, it is in a regulatory gene located far away down the chromosome that gets mutated in polydactyl cats. This mutation causes the regulatory gene to not work properly, which means that Sonic Hedgehog doesn't get turned on and off properly, and extra toes or fingers form.
Famous Polydactyl Cats
Some of the most famous polydactyl cats and kittens in the world live at the Ernest Hemingway Home and Museum. These cats are descended from a polydactyl cat gifted to the famous writer by a ship captain. According to the Guinness Book of World Records, the cat with the most toes in the world is a feline named Jake who lives in Canada and has 28 toes. The Milwaukee Animal Rescue Center has a 26-toed cat named Daniel who serves as a mascot and helps raise donations for the shelter.
Taking care of a polydactyl kitten is much like taking care of any other feline. In some cases, a polydactyl kitten might have more difficulty learning to walk or balance properly, but they typically adjust to their condition easily. In some cases, a polydactyl kitten can learn to do things a normal cat cannot, such as opening latches, because the extra digit gives the cat added leverage and dexterity. If you have a polydactyl kitten, clip her nails regularly to prevent ingrown nails.
Bridget Coila specializes in health, nutrition, pregnancy, pet and parenting topics. Her articles have appeared in Oxygen, American Fitness and on various websites. Coila has a Bachelor of Science in cell and molecular biology from the University of Cincinnati and more than 10 years of medical research experience.