Police were tipped off by a phone call about the house, on Bayonne Avenue in Central Islip, Suffolk County.
Responding officers and firefighters were shocked at what they found -- a crumbling home with no electricity, running water or sanitation, occupied by dozens of cats and a sickly elderly woman.
The site has been deemed a bio-hazard, because one of the byproducts of cat urine is ammonia, and it is unapproachable without a breathing apparatus.
The woman, identified as Rosemary Kobylak, was taken to the hospital against her will.
Firefighters, HazMat teams and Animal Control officers are in the process of removing the animals, at least 46 cats and one dog, one by one.
Neighbors routinely brought the woman food and water, but someone called 911 Friday morning after reporting that Kobylak appeared ill.
Given the conditions, authorities told Eyewitness News reporter NJ Burkett that it was amazing she is even alive it all.
Islip town officials say the house has at least a dozen outstanding code violations and that they've been in and out of court. The house was condemned a year ago, but Kobylak apparently ignored the vacate order.
"This house was deemed uninhabitable to live in, and yet she continued to come back to the house," Islip town spokeswoman Inez Birbiglia said. "And what you're seeing as a result today is many animals living in a house, and it's just deplorable."
Kobylak's condition is unknown at this time.