Nismo's owner Jess said she had turned around to make her son's lunch and was just putting the spread back in the cupboard when she noticed her dog was missing.
"We've recently moved house and it's not properly fenced. We're getting a fence put up on the weekend so this won't happen again," Jess said.
A district council spokesman said: "We like to promote public transport because we have so many commuters, it is nice to see pets are getting the message too."