The foster volunteer who took in the pups said they believe the one who died was either the runt of the litter, or might have been at the bottom of the plastic bag that was dumped behind an auto parts store in Coachella on April 18.
"He was just so weak and held on for as long as he could," the foster wrote in a Facebook post. "When I got him he was pale and kind of flat looking, so I think he was the cushion that saved his siblings."
The volunteer believes "he was at the bottom and took the hit when all of his siblings landed on him," but the other six dogs, who were around 3 days old when they were discovered last week, are "thriving."
Surveillance footage was released of 54-year-old Deborah Sue Culwell allegedly dumping the litter of pups. She was arrested at her home on Monday, where Riverside County Animal Services found and impounded 38 dogs living in squalor.
"Most of the dogs appeared to be in somewhat healthy condition, but some were aggressive or fearful," John Welsh, of Riverside County Animal Services, said in a news release. "The house was in a state of disrepair."
The 38 dogs are currently being cared for at the Coachella Valley Animal Campus in Thousand Palms, where veterinarians said none of the dogs appear to have serious illnesses.
Culwell, meanwhile, still maintains ownership of the dogs, according to Welsh. He said that each day the 38 dogs remain in the care of Riverside County Animal Services, Culwell is billed $570 in boarding and care fees. That number excludes the cost of "vaccinations, examination fees, medications, nor state-mandated fees" that are necessary for the dogs.
Officials said Culwell has 10 days to request a hearing to maintain or relinquish ownership of the dogs, but after that period is over, animal services can work to rehome the dogs.
Culwell faces up to seven felony counts of animal cruelty. According to online records from the Riverside County Sheriff's Office, she's scheduled to appear in court on June 18.