By Jim Lokay

Weymouth, MA (WCVB/CNN) - The death of a cherished dog at a Massachusetts day care facility has left the owner sad and angry.

It's also prompting an investigation into how the dog died.

"You know Cooper was our life and that's for us you know it's everything, it's everything we have," said Guy Reynolds.

The purebred English bulldog turned six last week and it was on the dog's birthday when their normal doggy day care was closed, so he ended up at the Land of Pawz.

"The day care facility for us is peace of mind, knowing that he's not home by himself that he's playing with other dogs and he's getting exercise and he's being watched out carefully and all that kind of stuff. So, um, that's what you're hoping when you drop him off there in the morning," said Reynolds.

At least he hoped.

"They called us at 4 o'clock in the afternoon and just said you know your dog had died," said Reynolds.

Cooper's vet says the cause was heat exhaustion.

Dogs rolled inside and out of the Land of Pawz. The owner wouldn't comment on what specifically happened, but unlike kennels, the state says doggy day care facilities don't face the same laws.

The Reynolds want that to change.

"You know it's tough. You know there's going to be some stricter regulations on day care facilities for sure," said Reynolds.

WCVB did speak with the owner of the day care facility, Tom Fleming. He says this was a tragedy and they're heartbroken, but also says the story isn't as it was presented.

Weymouth Animal Control officials are now investigating Cooper's death.

WCVB/CNN