It's a nightmare for most pet owners: A dog goes missing while in the care of someone else.

That's the scenario unfolding for one Vancouver family right now. What's worse is that the owners weren't notified until hours after it happened.

"We didn't sleep at all that night. We have two younger kids as well, so it has been highly emotional," said Michael Brennan.

Brennan’s wife had found a dog-sitter online using Rover.com.

The Seattle-based company connects dog owners with local pet-sitters who advertise through its website.

"I thought I have to have some trust in the service this person provides, this is what they do." Brennan said.

The family dropped off their two-year-old shepherd mix, Sami, at the sitter's home on Friday and left for a wedding on Vancouver Island.

Later that night, they received a message from the dog-sitter telling them that their pet was missing.

“He then said, 'I'm sorry, your dog is gone. I will no longer be responding to any more communication with you,' and that was it," Brennan added.

Brennan said he and his family could not catch a flight back home until the next morning to begin the search.

Lorie Chortyk with BC SPCA said the first hours are very important when a dog is missing.

"If you are looking after someone else's pet and they go missing, act very quickly," Chortyk said.

Brennan believes the dog-sitter may have not even been home when Sami went missing.

"We've received feedback that this person was caring for 5 or 6 dogs at a time," Brennan said. "We’ve also received notice that this isn’t the first time dogs have gone missing from this person's care."

In a statement to CTV News Vancouver, Rover.com said, “safety of those in our community is a top priority, and we are no longer allowing this sitter to offer services through our platform.”

The company has also purchased flyers to spread and is offering a reward.

Anyone who sees Sami is asked to call 778-558-0745.