What's this? Paw thing

[Foolsand]

My 4 year old collie got this circular thing on the outside of one of his toes last September. Vet said it wasn't a corn or anything.

February it turned black. I changed vets and asked a the new one what it was. She didn't seem to think it was anything.

Here is a recent photo. It almost seems a separate tissue from the pad. Does anyone know what this is????

Also it is part of the pad / it faces down within the pad area, just on the outer edge. If that helps anyone who has any idea?

Histiocytoma?

They normally wither and go away on their own but not always. If it starts to grow you might want to think about having it removed before it becomes big enough to be awkward to remove.

ok I googled histocytoma and definitely a few pics look similar to what ddog has....I had thought it might be a corn, vet said 'no' but didn't suggest tumour. (I don't know why either vet didn't identify it )

Does anyone know if this will be hurting him? Sometimes he just stops when we're out walking for no apparent reason. Also it doesn't seem to be going away....

Corns kind of grow inwards, rather than outwards.

Histiocytomas are 99% benign and usually go away on their own, but I've had one dog with one that was showing no signs of departing, so it was removed.

I'd ask the vet for a fine needle aspiration test just to make sure it's nothing nasty and then keep an eye on it if it's a histiocytoma. If it grows any more I'd think about removing it soonish if it's being reluctant to shove off on its own.

So, another trip to the vet, and a different vet again (though same clinic) and she said it's a callous. Who knew!