Members of a family from Waterloo, Ont., are distraught after their six-month-old Jack Russell pug ran off while they were going through U.S. Customs in Detroit.

The Wilckens were en route to visiting family in Atlanta when they were directed to an inspection area after crossing the Ambassador Bridge.

'My wife and my son, they were crying.'—Niels Wilcken

The family said they were asked to put their puppy, named Ash, in a cage while officers searched the vehicle.

“I put Ash in the cage, I did it myself," said Niels Wilcken. “He went into the cage with the leash and the collar on and I closed the cage.”

After the family finished with U.S. Customs agents inside, Wilcken said he was told to go retrieve his dog from the cage.

But as Wilcken came out of inspection, he saw the dog running away.

Nine-year-old son Joseph Wilcken is heartbroken over his puppy, Ash, running away, Joseph's dad says. (Courtesy of Niels Wilcken)

“As soon as I opened the door to come out of the office I saw one of the officers was chasing the dog," said Wilcken. “I don’t know, they were taking the dog out of the cage.”

Wilcken said he's heartbroken for his nine-year-old son Joseph, who loves the puppy.

"I didn't know how to tell my son about the loss. It was very hard for me. I couldn't believe I would have these kinds of feelings," said Wilcken. "I had tears in my eyes. It's a dog, but my wife and my son, they were crying."

Customs officers couldn't snatch the puppy before it took off.

“When I was walking back to the office, one of the officers told me 'You're clear to go,'" said Wilcken.

Wilcken said his family searched for hours for the dog, but it's still missing.

Anyone with information can email helpfindash@hotmail.com