A father and son were told to find another place to stay after more than 30 cats were taken from the home.
"In my 31 years of law enforcement, this is probably the worst living conditions that I have ever seen," Chief Paul Poirier said.
Poirier said investigators were tipped off about possible animal cruelty at the home on Hartshorn Road. After securing a search warrant, police officers, fire fighters and a health inspector entered the home.
"There's mold everywhere. The ceiling is falling down. There's feces and urine throughout the home," Poirier said. "You can smell it from out here as soon as you open the door."
The health inspector deemed the structure uninhabitable. Police said the homeowner's wife used to breed cats.
"She no longer resides here," Poirier said. "They used to have litters of cats. This is our first complaint, though, that we've received."
Authorities said the cats were found all over the home, from the basement to the attic. Some were hiding in the eaves. Many of them were loose, but others were in cages.
"They were in crates, three in a crate, four in a crate, and that's not regular standard for care of a cat," said Tona McCarthy, cruelty investigator for the Society of the Prevention of Cruelty to Animals.
Some cats had long hair, which was severely matted with feces inside the mats. Out of the 34 cats, only one was neutered and one of the cats is pregnant.
The cat breeds included Himalayan and Persian.
Investigators said they believe the cats could have respiratory issues from poor living conditions, but they're mostly in good spirits and are expected to make full recoveries.
"I think they just let it get out of control, and sometimes it's by accident," McCarthy said. "It's not always on purpose."
Police said charges are likely, but it's unclear if both the father and son would face charges.
The cats are being taken to the Pope Memorial SPCA of Concord-Merrimack County to be cared for until they can go up for adoption.