The Pennsylvania SPCA says the reward now stands at $1,000 for information leading to an arrest and conviction of the person of people responsible.
The female dog, Chloe, was found in the 700 block of Gray Street in the Germantown section on Sunday.
Chloe was being treated for her injuries but died on Monday night about an hour after being transferred to a specialty hospital.
Officials say the dog appeared to have been doused with an accelerant and set afire.
She had extreme burns on her entire body.
"This is an extreme case of animal abuse," Lisa Germanis, V.M.D, head veterinarian at the Pennsylvania SPCA's Shelter Hospital said in a statement.
The Pennsylvania SPCA's Humane Law Enforcement Department is investigating.
Officers have located the owner of the dog and determined that Chloe had been living near the location where she was picked up.
Based on the current investigation, officers believe that there were multiple witnesses.
Anyone with information is asked to call the Pennsylvania SPCA's anti-cruelty hotline at 1-866-601-SPCA.