Burlington, Vt., Police Lt. Jennifer Morrison told the Canwest News Service the dog named Michou was left in the van parked at the Burlington International Airport on Dec. 18.
"Everything we've got points to it being unintentional," Morrison said. "We don't know how or when the dog got into the car, but we do believe that the owner was not aware that this dog was in the vehicle at the time he grabbed his bags and went."
However, Quebec resident Pascal Bellon, 50, was given a $100 fine. He agreed to pay the veterinary bills and to give up ownership of the dog as well, the report said.
On Jan. 6 a passerby told an airport police officer there was a "foul odor" and sounds of howling coming from a van with a Quebec license plate.
The dog lost half its body weight, and after emergency veterinary care, was placed with a foster family, Morrison said.