The tiny puppy with the white and brown fur doesn't have a name yet, just a number: 917.
When he was found, the 8-week-old puppy weighed less than five pounds and had been left in the scorching sun, wearing a chain around his neck that weighed four times as much as he did.
He is one of 371 dogs seized by federal and state authorities last month in Alabama, Mississippi, Georgia and Texas in what authorities say was the second largest dogfighting ring in the United States.
Normally, dogfighters wait until the canines are at least half a year old before they chain them and expose them to extreme heat or cold as part of a brutal program to transform the dogs into fighters, according to American Society for the Prevention of Cruelty to Animals CEO Matt Bershadker.
This puppy was one of several "8- and 10-week-old puppies on heavy, heavy long chains" found during last month's raids, according to Bershadker. ASPCA investigators were present during the raids.
"What we saw on this property brought even our hardened investigators to their knees, so to speak," he said.
The dogs were placed in the temporary care of the ASPCA and the Humane Society of the United States. More than 250 of them -- including puppy No. 917 -- were brought to a converted air-conditioned warehouse, where the ASPCA is caring for them. The others are in the care of the Humane Society.
This month, CNN was granted exclusive access to the ASPCA's rehabilitation of the former fighting dogs. CNN is not disclosing the location of the rehabilitation center for security reasons.
Not only are the dogs getting medical treatment for malnourishment and injuries sustained in fighting, Bershadker said the canines also are getting "a personal behavior modification enrichment plan to maximize each dog's opportunity to be placed in a home."
The goal is to turn these fighting dogs into animals that can be pets or work as rescue and rehabilitation animals.
"What we will do is go to each dog individually and assess their strengths and their weaknesses," said Bershadker.
If he hadn't been rescued, 917 and the other puppies would have likely become typical dogs bred to fight. Some of those fights, prosecutors say, brought in as much as $200,000.
Getting the animal into top physical condition is often the priority for those who train fighting dogs, and that usually begins with a few months lifting a heavy chain.
Next the dog is put in "the keep," an intensive training program before its first fight. When deemed ready, the dogs will be put into the "fighting pit" -- either in a test fight or "the show," a fight in front of spectators.
"Those fights can last 30 minutes, an hour, two hours, even three hours," Bershadker said "That's where the physical wounds are sustained."
Although 917 was too young to sustain injuries and scars from a fight, many of the other canines seized in last month's raid show evidence of being in a fighting pit.
At the ASPCA shelter, Dr. Sarah Kirk conducts an examination on one of the rescued dog. On the table is a dog so skinny that his ribs and vertebrae are visible through his fur.
"He clearly hasn't been well cared for," she said. "His body condition score is probably 2 out of 9."
The cuts, scars and large tumor on his paw suggest a very hard 10 years for this animal, which likely made more than one appearance in the fighting pit.
Since arriving in the shelter, the dog has been dewormed and given medicine for fleas and to manage his pain. The prognosis is good: Kirk said she believes with the proper care this dog will have a good quality of life.
Raiding the dogfighting ring
Last month's raid on the dogfighting ring started with a sliver of information.
"In 2010 we got a tip from a drug defendant that there were high-stakes dogfighting going on in Lee County, Alabama," said Clark Morris, a federal prosecutor in Alabama.
That led to an investigation in Alabama that turned up more evidence of dogfighting in nearby states. Authorities executed 13 warrants in Alabama, Mississippi, Georgia and Texas, which led to 12 arrests.