Authorities said they found 113 dead cats in an apartment believed to belong to a cat hoarder, and dozens of sick adult cats were discovered in a nearby house.
None of the dead cats were more than two months old, police said.
Seaside Police and the Society for the Prevention of Cruelty to Animals of Monterey County discovered the cats on Tuesday, SPCA Sgt. Stacy Sanders said.
The officers were alerted by a property manager who discovered dead kittens during an inspection. He received another tip that more cats were moved to a nearby house.
There, another group of investigators found 51 adult cats that were alive but sick and abandoned.
"The cats were still living but were in an extremely horrible condition," said Sanders. "They were separated into two groups and kept in rooms with little or no ventilation. The soils were saturated in urine and feces."
The officers worked about six hours to recover all the cats, as an occupant of the house had lost count of how many there were there.
"We had to go through all the corners, separate each bed and chair," said Sanders.
SPCA staff members treated the cats that survived, and are in stable condition. SPCA spokeswoman Beth Brookhouser said most of those animals had respiratory infections, parasites and broken teeth.
Two underwent emergency surgery for life-threatening uterus infections. At least five cats were pregnant.
"It definitely makes you go home and hug your animals a little tighter at night," said Sanders, who has a dog and a cat.
There were no arrests and citations, but the Humane Society has referred the case to the office of the Monterey County district attorney to consider criminal charges of animal abuse. He refused to identify the alleged hoarder while the investigation is ongoing.
Sanders said authorities received tips that the cats may have been taken from the street. Officials are asking community members to submit photos of their lost cats.
"I hate to see any of these hoarding cases," said Brookhouser. "All of them are tragic in their own way, but for me personally, this is the first time with so many dead cats."
