Stolen Dog

[slapshot21]

We purchased a small dog (Brussels Griffon) from a local pet shop in Reno, NV. The owner of the petshop sold the dog to us for $600. This was alomst 2 years ago. We had a hard time initially getting all the paperwork from her, but in time, we got what we needed. We have never heard or seen from the petshop owner since.
Two weeks ago or so, our dog discovered the art of digging under the fence, and escaped. She has a tag with our number on it, as well as a tag for her microchip from Homeagain Pet Relocating Service. This chip was registered to the old owner which we didn't realize until now. Well, our dog was returned by a neighbor around the block by using the phone number, but they also called the service. Luckilly I picked up the dog because ten minutes after I left, the former petshop owner went to the house to pick up the dog. The man who found her said she was in hysterics. I thought this was weird, so I called the phone number for the microchip place. They said that the dog was registered to the former owner, and I could request to transfer the registration to us. Well two days later, before I could send the paperwork in, our dog escaped again, this time through one small spot that I didn't block off. Well the people who found her didn't call our number on the tags, they called the relocating service who tried to call the registered name. Her numbers were disconnected, and by chance, she called the relocating service to deny our transfer request, saying it was her dog.
So now this former pet shop owner (who is long since out of business) has our dog, and won't call us back. We do not have her number because the reloating service won't give it to us. We had an address from her paperwork she gave us, but the home is being forclosed.
My main question is, is this a small claims issue? What can we sue for? I know punitive damages are often awarded in civil cases to "teach businesses and people a lesson" that they can't do these types of things. What type of award should we pursue, or is there other information that can help us? Thanks!

You could file a police report for theft/conversion.

And sue in small claims. That is not her dog and she must return it.