i think he did well

His brain to mouth filter failed.

Kind of reminds me of the time were throwing a surprise 80th birthday party for my grandma and my little brother was crying afraid the surprise would kill her. My awesome 14 year old soothing technique was to say "but she IS going to die someday. Our parents are going to die, I'm going to die. Even you're going to die." needless to say, he kept crying.

Dad jokes have a time and place to be told. Sorry for your loss OP

Poor child. Death affects everyone differently.

Sounds like his heart was in the right place. It's hard to know what to say when you lose a pet, because the only thing that will make it easier is time. I'm sorry for your loss.

I think a puppy might have been a better idea...but it's worth a shot

Sorry for your loss, OP

She probably would have cried regardless of what was said. That's normal, her dog just died.

I'm sorry about your dog, it's hard to lose a pet and I can relate because I was the same amount of upset when my first cat died. When the time's right, take your daughter out to pick a puppy. It eases the pain a bit