Alex said Nieves was one of two Maltese dogs waiting to be picked up at the same time.
The dog Alex's dad collected was the other one.
"According to him it was because the dog acted normal and followed him to the car and even jumped in as soon as he opened the door," he said.
Alex said that his dad thought he was joking when he pointed out that the dog he brought home was not theirs until his brother agreed. Then their dad said he knew something was off.
He added: "My brother and I died of laughter and asked why he would take the dog home if he thought something was off. He said, 'I thought I was getting old and my eyes were betraying me.'"