Polydactyl cats have more than the usual number of toes. The normal number is five on each of the paws of the front limbs and four on each of the paws of the hind limbs. Polydactyl cats have 6 or 7 on the front and 5 on the rear. They have strikingly over-sized paws and Catherine has described her cat, Big Foot, who certainly has one of the biggest paws that I have seen.
It seems that the extra toes can lead some cats to being more dextrous with their paws. Valley Girl lives with a polydactyl Maine Coon, Tootsie, and talks about this (new window). It is said that the extra dexterity comes from opposable inner toes in some polydactyl cats. Human thumbs are opposable because they can touch the fingers. They move in a different direction (towards the fingers) which allows us to grasp things. The same applies to cats that are polydactyl. Is it possible that this ability to be more dexterous has indirectly made these cats smarter through using their paws to grasp objects etc.? See too: Cat Intelligence.
I think that there are four natural topics to discuss on this subject: their origins, what causes polydactylism, whether there are any associated health problems and what about the breeding of this cat?
Incidentally, two other names (there are more) for cats with more than the usual number of toes are:
- Cardi cats – named after Cardiganshire in South West Wales (UK) where there is a higher than average population of polydactyl cats. This is perhaps because this was and is a shipping area and sailors considered these cats better mousers and so they were ships cats.
- Hemingway cats – the author Ernest Hemingway who kept cats one of which was polydactyl. These is now a colony of them. See American Polydactyl Cats (new window).
Origin of Polydactyl cats
Well, some Americans say that they are unique to the United States, which is not true – sorry – I hope the special relationship is not damaged. They are found in the UK and in Europe generally and why not? Genetic mutations of domestic cats have no reason to be confined to North America, surely.
There is the argument that they were imported with the Puritan settlers that landed near Boston. Although others argue that these cats were already there. However, it is now accepted that the domestic cat comes from the European and African-Asian, wildcats. This being the case it would mean that the importation theory must be correct.
The importation theory is supported by clusters of polydactyl cats in places where ships from Boston would have travelled to at the time (1600s and later), namely Yarmouth, Massachusetts and Halifax, Nova Scotia. See map below:
Charles Darwin referred to six-toed cats in his book The Variation of Animals and Plants Under Domestication, Volume 1.
The book was published in the 1850s apparently. Although the cat fancy had yet to really start deliberate cat breeding at this time, breeding was probably taking place in England before then. It is said breeding of cats in Paraguay started 300 years earlier!
How – genes
Polydactyl cats carry a mutated dominant gene – Pd – that causes this congenital defect, charming though it is. Although this (according to Robinson’s Genetics) is the only known gene, implying there may be others. The authors of Robinson’s genetics say that this condition may not be caused by a single mutant gene
There are two forms (a) extra digits on the inside (thumb side) and (b) on the outside. This is a dominant gene with variable expression. One of the expressions of the gene causes harmful medical conditions such as radial hypoplasia. There is a cat type called the Twisty Cat that is controversial and which is an example of one of the various types of expression of this gene.
Polydactyl hind feet only exist when the condition is present in the forelimbs.
There are breeders who want to create a distinct breed from polydactyl cats. There is the American Polydactyl Cat for instance and another is the Ithacats.
One breeder I think worth mentioning is Polypaws (new window). They seem to be exclusively concerned with breeding polydactyl cats. I am not sure where they are but it seems to be about 35 miles west of Indianapolis, USA. I am not sure if they are still trading. The other few breeders on the web left me uninspired or looked like they were not functioning.
So, breeders are rare and frankly that seems to be correct. Breeding seems to be confined to the USA.
Polydactylism is caused by a gene that nearly always confines itself to creating extra toes so there are no outstanding health issues except for the one referred to above: Twisty Cats which have a deformity that is caused by one of the variations of the gene causing polydactylism. Twisty cats have deformed forelegs akin to the limbs of people who suffer from the drug thalidomide. The name “twisty cats” is a cruel misdescription. The long bone of the leg is a vestige of its normal self (or shortened) and the paw is almost attached to the shoulder in some cases. This makes it hard to walk. The hind legs do most of the work. It is not a mutation that would pass the test of Darwin’s natural selection and is only propagated through deliberate breeding albeit in a very small scale thankfully. I criticise the CFA for not taking a tougher stance on this sort of cat breeding. The video however, shows a cat that is pretty active to be fair.
Photos: Both published under Attribution 2.0 Generic, creative commons license