DEW CLAWS.
Some dogs have dew claws on there two front legs ,and some have them on all four legs ,They are removed when pups by a lot of owners as they can get ripped causing bleeding ,wolves, African wild dogs, dingos,and most of the big cats have them ,they have found dinosaur's with dew claws ,some are attached to the leg by solid bone and others are attached by muscle
They are thought to help when digging for prey in hard ground