Consider brown bears and polar bears. We consider them 2 species yet they can successfully interbreed. The main reason they don't is that their ranges haven't historically overlapped. Geography, not biology, was the separator. You could view them as one species with a bivariate distribution, in the late stages of diverging into two.
Canids likewise viewed as one species with significant ecological clustering, but divided this time by behavior.
The long nails (I wouldn't call them claws) look like a dog that doesn't get outside much. If a dog is outside, walking around, digging etc the nails get ground down and would be much shorter. If this were a wild animal, those nails would definitely be shorter.
I would say this was a house pet in the very recent past (whether a dog, or some wolf-dog type animal).
Agreed that this seems likely. There's the Eastern coyote which is a hybrid of Western coyote with Eastern wolf and some dog thrown in the mix. Those paws definitely look doglike to me.
