A dog left for dead 500 miles from Dallas is on the road back to recovery thanks to the help of a North Texas non-profit.

"He's still trusting and loving of humans even after everything he's been through," said Mark Verma, president of the animal non-profit Paws in the City.

Sid's story starts in South Texas, Cameron County, just minutes from the border. The dog was picked up by animal control. Sid was badly bruised and cut, but most disturbing of all was what the dog was missing.

"He had his teeth pulled," Verma said. "At first we were in disbelief of that but X-rays show that there are fragments still remaining in his gums that are going to have to be surgically removed by the vet."

That's when Paws in the City, a Dallas non-profit stepped in. Through its network of volunteers they moved Sid to a foster family in Forney in May. Since then, he's slowly gained weight and appears to be headed in the right direction.

That's thanks in large part to donations that have poured in from around the country.

LINK: GoFundMe: Sid's Story

"Sid would have been euthanized," Verma said. "He would have been put down. Not only is that an overcrowded rural shelter that he came from, but his medical conditions are not something that they could have handled."

Sid isn't in the clear just yet. He still has more surgeries ahead of him and is still looking for a permanent home. He's also relearning basic skills like drinking water on a hot summer day.

"It's amazing that he's even able to open his heart and his mind and let us in to help him," said Lori Pierce, Sid's foster mom.