Police were called to the ramshackle home last Friday by the neighbor.
Officials say they removed 50 cats over two days from the house, where they found the animals surrounded by months of piled up feces, a flooded basement and missing sections of the roof. Authorities say the home had no heat or running water.
Investigators believe the property's owner dropped off water and food for the cats. The homeowner hasn't been charged.
The cats are being cared for by the Niagara SPCA. Most of the cats are expected to be adopted.