Authorities in Pasco County found the truck in a Publix parking lot in Spring Hill, reported the Miami New Times.
Officials said they could hear the cries of animals inside the U-Haul. When they opened the vehicle up, they discovered 50 cats and three dogs.
They were stored in individual plastic containers in the “extremely hot” truck, officials said.
Nearly 40 of the cats were forced to be euthanized on Tuesday, reported WTSP-TV.
“I’ve been involved with numerous hoarding situations during my veterinary career and this was very similar to other cases I’ve seen,” Dr. Lisa Centonze, the chief Vet for Hernando Animal Services, told ABC Action News.
She added that in places “where the cats are so crowded and so neglected and stressed out from the overcrowding that they break with upper respiratory infections.”
Dr. Centonze said that of the dozen or so animals remaining, they are all adoptable.
Frances Evans, 50, was determined as the suspect in the case after authorities found out she rented out the truck, according to the New Times. She was already the suspect in an animal hoarding case.
Evans was arrested after she was located by authorities. She was charged with 53 counts of animal abandonment and will face 53 charges of animal abuse.