They found five cats alive, four dead. They say they know there are more in there. They've set traps and will return Tuesday to retrieve them.
Meantime, the 75-year old property owner remains in the hospital and faces numerous counts of animal cruelty.
"In 20 years, i've never seen anything like this," said George Bengal of the Pennsylvania SPCA.
It is the worst case of animal hoarding veteran SPCA officials say they've ever seen.
They spent the afternoon removing more flea-infested, sickly cats from 9150 Bickley Street in the Northeast. The house with the overgrown yard is filled with feces, bats, rats, roaches and fleas.
"This blows away any house i've ever been in," said Bengal. "That's how bad this house is inside. I can't image a human being living inside of this property."
The SPCA said this house was not on their radar before Sunday night. The homeowner, 75-year-old Richard Garafolo, had called his grown children who live in the area and told them he had fallen and couldn't get up.
They came to the house and couldn't get inside. They saw the food they'd left for him had gone uneaten and called police. Garafolo was found unconcious inside the crumbling home filled with cats both alive and dead, some decomposing.
"I never knew he had that many animals in there really," said one neighbor. "I thought he only had the one cat. That's all I know."
The roof of the home is caving in, the basement filled with 2 feet of water. Licenses and inspections condemned the property as unfit for human habitation.
Neighbors saw Garafolo and his cats. He wasn't friendly, and they figured he just wanted to be left alone.
"One time his mail came to our house. We had to take it over there. He opened the door just a little. This chlorine kind of smell came out," said Giorgi Butkhuzi.
"To let your father live in those conditions without doing anything? I have a hard time with that," said Bengal.
Officials at the scene said they believe the house will have to be torn down. The SPCA says hoarding cases are way up around the region. They're trying to figure out why and how to better educate the public so that situations like this one don't get so out of hand.