A polydactyl cat is a cat with a congenital physical anomaly, with more than usual number of toes on one or all of its paws as a result of a cat body type genetic mutation. In animals including humans, polydactyly (or polydactylism, also known as hyperdactyly) is the anatomical abnormality of having more than the usual number of digits on the hands or feet.

Description

Normal cats have four toes and one dewclaw on each front paw and four toes on each hind paw. Polydactyl cats may have as many as seven digits on front and/or hind paws, and various combinations of anywhere from four to seven are common, although each of the front and rear paws are typically the same. Polydactyly is most commonly found on the front paws only, with polydactyly of all four paws being less common. It is rare for a cat to have polydactyl hind paws only.

The true polydactyly - commonly called mitten foot, mitten cat or thumb cat condition - is a congenital abnormality, genetically inherited as an autosomal dominant trait of the Pd gene with incomplete penetrance. This type of polydactyly is not life-threatening and usually not even debilitating to a cat. Some polydactyl kittens initially have more difficulty in learning to walk and climb than normal animals. However in some cases it appears to improve the dexterity of the animal. For example, a common variation of polydactyly with six toes on the front paws, with two opposing digits on each, (comparable in use to human thumbs) enables the cat to learn and perform feats of manual dexterity generally not observed in non-polydactyl cats, such as opening latches or catching objects with a single paw.

Feline radial hypoplasia (see squitten) is a mimic of polydactyly and is considered a severe condition. Radial hypoplasia may cause the formation of extra jointed toes, but it is not a result of the Pd gene normally associated with polydactyls. It thus does not cause the "mitten cat" or "thumb cat" condition where the extra toes occur separated from the normal ones just like a dewclaw, usually associated with an additional pad which makes them look like a underdeveloped foot sticking out near the base of the normal toes.

Rather, radial hypoplasia-related extra toes are immediately adjacent to the normal ones, giving the cat overly large, flat feet - colloquially known as "patty feet" or "hamburger feet". Though this looks less serious than true polydactyly (as the feet appear "normal" apart from having one or two extra toes), breeding such cats will eventually result in severely crippled offspring that will have to be euthanized. Cats used in polydactyl breeding programs can be screened by x-ray for indicators of radial hypoplasia, and cats suspected to have radial hypoplasia should not be used for breeding.

History

The condition seems to be most commonly found in cats along the eastern coast of the United States and in South West England. Some sources state that these cats are rare in Europe because they were killed as witches' familiars, but other sources indicate that they are quite common in England. Polydactyl Cats are very common in the Cardigan area of Wales and are known as Cardi-Cats. A Canadian cat called Tiger was recognised by Guinness World Records as having the highest number of toes on a cat, with 27 toes.

Although there is some controversy over whether the commonest variant of the trait originated as a mutation in New England or was brought there from England, there does seem to be agreement that it spread widely as a result of cats carried on ships originating in Boston, and the prevalence of polydactylism among the cat population of various ports correlates with the dates when they first established trade with Boston. Contributing to the spread of polydactyl cats by this means, sailors were long-known to especially value polydactyl cats for their extraordinary climbing and hunting abilities as an aid in controlling shipboard rodents. Some sailors also considered them to be extremely good luck when at sea.

Breeds and Varieties

Nobel Prize-winning author Ernest Hemingway was one of the more famous lovers of polydactyl cats, after being first given a six-toed cat by a ship's captain. Upon Hemingway's death in 1961, his former home in Key West, Florida, became a museum and a home for his cats, and it currently houses approximately sixty descendants of his cats (about half of which are polydactyl). Because of his love for these animals, Hemingway cat, or simply Hemingway, is a slang term which has come to describe polydactyls (Michael Palin describes one such cat named "Bill Clinton" he found at a former residence of Hemingway's in Key West during the filming of his "Hemingway Adventure" special).

Other nicknames include "boxers" or "boxing cats", "mitten cats", "thumb cats", "six-finger cats", "Boston Thumb Cats", "Cardi-cats" and "double-pawed cats" (a misnomer since there is a specific double paw condition).

American Polydactyl Cats are also being bred as a specific cat breed, with specific physical and behavioral characteristics in addition to extra digits. A particular strain native to Ithaca, New York, is known as the "Ithacats". The American Polydactyl is not to be confused with the pedigree Maine Coon polydactyl. The polydactyl form of the Maine Coon is being reinstated by some breeders. Thanatos Cattery, Inc. , a primary breeder of Ithacats, is a prolific and renowned breeder in the area. John Thanatos himself typically breeds the cats.

Polydactyly has also been observed in big cats.

Additional Images

References

• Chapman, VA; Zeiner, FN: The anatomy of polydactylism in cats with observations on genetic control Anatomical Record 141:205-217, 1961
• Danforth CH: Heredity of polydactyly in the cat. Journal of Heredity 38: 107, 1947
• Danforth CH: Morphology of the feet of polydactyl cats. American Journal of Anatomy 80:143, 1947
• Jude, AC: Cat Genetics, 1955
• Robinson R: Genetics for Cat Breeders, Mar 1977
• Sis, RF; Getty, R: Polydactylism in cats Veterinary Medicine and Small Animal Clinician 63:948-951, 1968
• Todd, NB; Jones, TC: On independent assortmant of dominant white and polydactyly in the cat Journal of Cat Genetics 1:16-17, 1964
• Vella, C; Shelton LM; McGonagle J; Stanglein TW: Robinson's Genetics for Cat Breeders and Veterinarians, Butterworth- Heinemann Ltd (19 Aug 1999)
• Wenthe, M; Lazarz, B: A case of atavistic polydactyly at the hind limb of a cat [German] Kleintierpraxis 40:617-619, 1995
• Wittmann, F: Polydactylism in a Cat Praktische Tierarzt 73:709, 1992

External links

• Hemingway Home Museum, Key West Florida, cats webpage
• Different Types of Polydactyly in Cats
• Maine Coon Polydactyl International
• American Polydactyl Cats
• Article on polydactylism in cats in New England
• Polydactyl Cats Photo Gallery online
• Images of polydactyl cats
• Maine Coon Polydactyl Tracking Database and Resource
• Owner's appeal over cat's 26 toes