More than a dozen dogs rescued from a squalid house in Holyoke are being nursed back to health by bighearted staffers at a nearby adoption center as the man who left them to live in their own filth is behind bars on animal cruelty charges, police said.

“All of them were living in squalor. We don’t know how much food or water they had. When we were there, there was none available,” said Pam Peebles, executive director of the Thomas J. O’Connor Animal Control and Adoption Center in Springfield, which took in 14 dogs rescued Thursday from a foul Newton Street apartment. Unfortunately, she said, one dog discovered by police was already dead.

“We were told the owner was sneaking into the house to see them when he could,” Peebles told the Herald. “It was like survival of the fittest. … Four of the dogs, weight-wise, their physical body count score was low.”

The dogs, she said, ranged from 8-month-old puppies to 8?years old.

One Chihuahua puppy was just 4 pounds — less than half its ideal body weight — and covered in lesions.

“All of them suffered from a massive flea load that was causing them to suffer from anemia since the fleas were taking so much blood from them,” Peebles said. “Their bedding was coated with thousands of dead fleas.”

Holyoke detectives investigating the situation arrested Julio Rivera, 49, of Holyoke on 17 counts of cruelty to animals.

Holyoke police Sgt. Kevin Thomas said officers searching the house found it infested with fleas and littered with dog feces and urine.

Peebles said workers at the center are ecstatic to see how quickly many of them are bouncing back. Pictures posted to the center’s Facebook page showed many of the dogs pig-piling onto staffers and wrapped in warm blankets after getting much-needed baths and nail trims.

“They’re doing amazing. There were a few that we were worried about. Of course we’re worried about them all, but three we considered guarded. Some were still dehydrated a bit, but they’re coming around,” Peebles said. “It’s unfortunate, but it’s really common for us, sadly.”

Area residents interested in taking in one of the dogs will have to wait until the criminal case moves forward, Peebles said.

“We’re unsure about adoption. It depends on whether the owner wants custody of them,” she said. “We maintain ownership as they’re being held as evidence.”

Police say Rivera will be arraigned tomorrow in Holyoke District Court.