Environmental officers seized the 340kg, 3.4m/11ft-long alligator called Albert from a home in Hamburg, south of Buffalo, where they found a swimming pool for the 30-year-old gator.
According to the state department of environmental conservation, the homeowner allowed people – including children – to get into the water with the reptile, which had blindness in both eyes and spinal complications.
The owner’s licence to keep the animal expired in 2021, meaning it has since been kept illegally.
Officers took action on Wednesday after learning the “extent at which the owner was seriously endangering the public”, according to a statement from the agency.
But Tony Cavallaro said Albert had been with him since the 1990s and promised to fight for his return.
He said he treated the alligator like it was his kid and that he never put anyone in danger.
“I’m not dangerous, I’m not being unsafe with people,” Mr Cavallaro said.
State environmental officials haven’t decided whether to bring charges.
The reptile has been sent to a licensed caretaker until a place is found where it can receive permanent care, according to the agency.
