Dang, turns out dogs are laughing after all. You know, when their tongue is hanging out and they're puffing and panting. They really are laughing, at least some of the time.
When I was a youngster I always used to assume that dogs were laughing, until I ran across some tidbit from a debunking naysayer ("NOOOOOOO!") who asservated that it's just a dog's way of perspiring.
Which it is, much of the time. But now it turns out that certain "dog laughter" has a very distictive profile spectrogram-wise, and "appears to be a vocalization exclusive to play encounters and friendly encounters with other dogs and people. This vocalization is a signal to reinforce play, a signal to initiate play, and to demonstrate good intentions."
Reminds me of the old Talking Heads song:
I know the animals... Are laughing at us
They don't even know... What a joke is
I won't follow... Animal's advice
I don't care... If they're laughing at us.