MEDIA, Pa. (WPVI) -- Sly, named for 'Rocky' actor Sylvester Stalone, is a fighter.
The large but emaciated dog is still sedated and recovering from surgery, but he still managed to lift his head for a post-op visit from Dr. Gia Croce at Providence Animal Center in Media on Wednesday afternoon.
"Hopefully he'll be able to live a very long life. This should be but a little bump in the road for him," said Croce, one of Sly's surgeons.
His prognosis was not so positive about 24 hours prior.
Investigators say a humane officer was called to Deshong Park in Chester around noon on Tuesday when a contractor noticed a dog in the park struggling to breathe.
"It was right along 11th Street. He saw a dog on a blanket and he was a bag of bones and he couldn't lift his head, " said Justina Calgiano with the Providence Animal Center. "He was kind of tucked in behind a tree and he had just been discarded there."
It's one of the worst cases of emaciation officials say they've ever seen.
He underwent emergency surgery where doctors found an intestinal blockage, what appears to be a rope chew toy.
Humane officers are still gathering information, but say charges are likely.
They do suspect Sly had recent medical treatment because of a shaved patch on his side.
They also say one possibility is that Sly's owners found out that he needed expensive surgery and abandoned him.
Shelter officials say in cases like this they can help.
"The emergency surgery we did for Sly yesterday is something we do on a regular basis for families in the community that have received an astronomical quote from a private practice," said Calgiano.
Shelter officials say Sly's surgery and continuing care will cost thousands of dollars.
If you'd like to donate, you can make a donation online in Sly's name