If you ever put a dog to sleep DON'T WATCH!
I thought this was a comedy for kids. If you have ever had to put a loved pet to sleep don't watch. It is like reliving the vet visit. If you want to show this to kids stop after the trip to the vet and the kids bus ride home where Marley is waiting. That would make a good ending for kids or sensitive family members. I personally will not watch it again.