when dogs dream

The other day I was watching Isaac sleep - I always look to see if he's dreaming. He's quite active in his dreams. He barks and runs or sometimes even growls and sniffs. It never seems particularly pleasant, more aggressive. He could be dreaming of playing with other dogs or maybe chasing squirrels, but something always keeps me from deciding it's anything that good.

For once, though, as I was sitting at the dining room table I heard a thwacking. I knew he was wagging his tail, but I wondered at what. He was dreaming. Eyes closed, a good dream! It made me glad because I always worry that he is reliving some trauma from before we adopted him. But now I know that he does have pleasant dreams, and if the other ones have been traumatic, maybe it means he is working through them.

Still, I wish I could ask him what he dreams. And whether he knows the difference between being asleep and being awake. I mean, it's hard enough for me to be sure sometimes.