Does your cat have what appears to be "more than one paw" on each hand? Well, it sparked my interest when I met a cat that had this apparent mutation, so I did some research and was baffled at my findings.
Scientists in the Netherlands wrote a study on this phenomenon about 30 years ago. What they found was that as kittens grew in the womb of the mother cat, at times two kittens would fuse together. It is hard to understand, we know, but in cats , it is possible for two fetuses to begin to bind together, kind of like how humans are just many different cells bound together to make one organism.
The double paw means that your cat is actually two cats merged together, and as seen in the cat above, it appears this one was a black cat and a white cat made into a tuxedo cat. Double paw cats are adorable, and contrary to popular belief, aggression levels are practically non-existent.
Rumors say that double pawed cats also have double canine fangs, this is false, but I must admit, this cat's gaping mouth opens wide enough to perforate the human aorta -the preferred striking zone for any cat-.
So in the end, whenever you see a double pawed cat, it truly is a perfected conjoined twin. A mutation which has somehow overriden the bias that conjoined twins are a negative thing.
And is this beneficial to this cat? Absolutely, all fingers, nails and joints on the paws are fully functional. They are well vascularized , and very sensitive , like a standard cat paw. The nails also grow naturally, as if the hand had never been joined.
Lifting the paw does not bother the cat , in fact, this cat began to wrestle with my arm, and it easily overpowered it. No pain seems to be present upon the touching of the conjoined paw, and the regular reflex of contracting the nails occurs upon pressure appointed from both sides. The cat does have a strong tendency to clean it's paws, from personal observation.
So in the end, this is a cool mutation, a beneficial one as well if your cat likes water, hunting, or walking. And there is nothing to fear, it is more common than you would think :)