No.

Dogs make a lot of facial expressions. They can certainly bare their teeth out of fear or aggression. That's much different from a dog wagging its tail and grinning when its owner comes home and is ready to play. Dogs can have a sense of humor, and they can grieve as well.

We don't want to anthropomorphize animals too much, but we also don't want to strip them down to robots and pretend they don't have emotions. They certainly do.

I have spent over a decade working with animals.