My parents dog had to be put down a couple years ago. My dad n I went in the vet's office, not knowing for sure if it was his time, but, he was suffering. We both cried quite a bit, I've never had to put a dog down. I know he was just a dog, but, definitely the smartest dog we ever had & part of the family. He was some sort of lab mix, maybe with border collie? It's taken me so long to not expect to see him laying next to the sliding door at my parents house whenever I go there. Even now, I occasionally expect to see him there.