ROSEVILLE, Mich. – Surveillance video shows two men in a Chrysler 200 pulling behind a Walmart in Roseville where they abandon a dog.

When the men leave, the dog is shown chained up and looking for its owners. The dog was looking for help.

The video is from Monday. Rescuers have named the dog "Courtney." When the men dumped Courtney behind the store the dog was suffering from life-threatening injuries.

She was left cold and hungry. The dog became wrapped up in the cable used to chain her up outside. Melanie Wittner, of Hopeful Heart Animal Rescue, said Courtney made an excruciating decision.

"She ate her paw because she was trapped in the cord," said Wittner. "Pretty desperate. Really desperate. With the cold weather we've had she was probably out there freezing. She had no way to stay warm."

The dog needed critical, life-saving care. Diana Rascano, of the group 4 Paws 1 Heart, used donations to pay for veterinarians to amputate Courtney's leg where she chewed off her paw. Another surgery was needed to remove her own bone fragment from her stomach.

"Dog like Courtney was probably an outdoor dog. She just was probably kept on a chain, never to be brought in or loved," said Rascano.

As for the two who left the dog, there is an active investigation underway to find them.

"There is enough clarity within the video to show that two black males got out, took the dog out, chained it to the fence, and then just drove off," said Roseville Police Chief James Berlin.