double claw

I have rescued a cat 3 weeks ago with many many health problems.All of them have cleared out after seeing 2 vets and lots of treatments.He looks like a mix maine coon and his age is unknown, estimated between 1 and 4 y.
This morning during the claw trimming I've discovered something very weird: this cat has double claw at 6 or 7 of his toes. He is not a polydactil because he has 18 toes. These additional claws are very distinctive and grow from his toe pads.They are miniature claws and they only grow like 1-2 mm. I trimmed them and check the consistency and it looks like a genuine nail.
I'm not sure that I can take a picture of them but I'll try.What I'd like to specify is that these claws/nails are completely independent and not part of the regular claw but growing directly of the toe pad.
Any ideas? Is this a genetically defect?

Here is what I found. This is what my cat has to 6 of his paws. I've read other articles saying that these are callouses.
http://messybeast.com/horned-paws.htm (second set of pictures from the top 1st picture on left)

I've seen that before on a cat. IMO its not a true polydactyl but it has to do with that gene were you have an extra claw but not an extra toe. Be careful of them and keep them trimmed - check often cause they could cause problems later on as the cat gets older.

Thank you.I'll keep an eye on him.

Hey there!

I have a cat ("Tiny Dancer") who has about 5 double-nails, but for him it is genetic. He was born with radial Hypoplasia, so he never even walks on his front paws, but on one forearm. The nails on Tiny are very, very loose (even though he does use the scratcher as he can), and he also has a couple of "hash" nails. They are all regular nails, some coming from the pad, some on the side, then the regulars in the regular place.

Speaking of that, I have an extra lumbar in my lower back and also an extra rootless tooth floating in the roof of my mouth. Born with too many bones, cats and people! lol

By the way - WELCOME!!! Really look forward to seeing your beautiful, beloved cat!! :-D

Came across something like this on my cat but it looks to have been bleeding at some point. Doesn't hurt him at all though. Did your double claw look like this? He is also polydactyl so I do wonder if there is a link to having this extra claw if that is what this is.