Officials went through the Monroe home about 10 a.m. after serving a search warrant, the police said, noting that previous attempts to contact the owner had been unsuccessful.
Neighbors' complaints about bad smells and "a large amount of flying bugs" coming from the residence were what prompted the search, police said.
Officials reportedly found 23 cats alive and 14 dead. One dead cat was in the freezer, police said.
Animal feces were strewn about the house, while cats roamed the yard, The Daily Herald reported. Crews had to wear protective clothing and masks while they worked, the report said.
“The living conditions were deplorable,” said a statement from Monroe Police.
Police said the live cats were taken to the Everett Animal Shelter for evaluation. The 83-year-old resident of the home, whom police found after entering, was taken to a local hospital, police said.