Polydactyly in Cats

Polydactyl cats can be found throughout several parts of the world including; Asia, Prince Edward Island, Nova Scotia, Great Britain and the United States. Boston, Massachusetts holds the largest population of polydactyl cats, believed to be descendents of the feline brought to the US by English Puritans. Sailors believed the extra toes of the polydactyl cats made them better at catching mice than the average cat, therefore, many of the mutated cats came to live in different parts of the world by boat. It is for this reason that polydactyl cats are found in higher populations around sea ports. 

Polydactyly in cats is a condition in which a feline possess more toes than the average cat. Felines are born with fives toes on each front paw and four toes on each back paw, but polydactyl cats have several. The increased number of toes is an inherited, genetic mutation that is not uncommon. In fact, many breeders intentionally breed cats containing this genetic abnormality to meet high demand of what pet owners consider a cute physical characteristic. Breeders often advertise these felines as “mitten kittens,” “cats with thumbs,” or “big-foot cats.” Although related health conditions are minimal, breeding polydactyly in cats simply for the gratification of human ownership is highly discouraged. 

Polydactyly in cats holds a primary clinical sign of extra phalangeal growth on each paw. The extra digit varies in structure, consisting of only soft tissues or connecting to inappropriate bone structure, making the feline prone to injury. The nail beds of the extra toes can be fused together at birth, resulting in painful claw abnormalities due to irregular growth.

• Nail overgrowth 
• Irregular nail growth 
• Nail bed infections 
• Injury
• Pain 

Types

Polydactyly in cats has two known types; preaxial and postaxial. 

• Preaxial Polydactyly: The extra digit grows before the dew claw. 
• Postaxial Polydactyly: The extra digit grows after the fourth phalange (toes).  

Polydactyly in cats is an inherited, genetic mutation passed down from parents to offspring. Polydactyly in cats is the result of a single, autosomal dominant gene, which means that mutated gene will override other normal genes. Therefore if one parent possesses the polydactyly gene, but the other parent does not, the kitten is still likely to develop the condition.  Maine coon cats are the common feline breed prone to polydactyly.

Polydactyly in cats is primarily diagnosed on physical exam, as the extra number of digits are visible. The veterinarian will discuss the feline’s parents, the breeder from which you purchased the feline, and any noted health complications the extra digits are afflicting the feline with. The veterinarian will feel the affected paws to determine whether the extra toe is simple tissue growth or bone. The hypothesis made as to what a polydactyl paw is made up of can be better diagnosed upon radiographs of the paw. An assessment of the feline’s health, including a blood and urine examination, may be conducted if infection is present. 

Polydactyly in cats may not require treatment, as breeders actually use selective breeding practices (the act of personally selecting a male and female to mate, producing offspring with favorable traits) to gain this mutation in offspring. However, polydactyly in cats can cause lameness and infection, and the mutation of genes can spread to other part of the body, resulting in complications with the heart which require euthanasia. In minor cases of polydactyly in cats, surgical removal of the extra digits is commonly performed to avoid injury and health problems in the future.

Cats that undergo surgery will require anesthesia during the surgery, but it is not common for a feline to remain hospitalized overnight. Pain medications are likely to be sent home with the feline, paired with an antibiotic to prevent a bacterial infection. The use of litter in your cat’s litter box is discouraged during recovery time, as the sand could easily become lodged into the surgical opening. The feline should make full recovery within a few weeks. 

Polydactyly in cats is highly discouraged in breeding practices and is readily unadvised by veterinarians. Using selective breeding for human gratification is often considered inhumane due to the health complications that accompany the genetic mutation. Felines that possess this mutation, both male and female, are routinely sterilized to avoid carrying the mutation to future generations.