Originally posted by Eeyore
I have a labrador who does that. He does it when he's really excited to see someone who is equally excited to see him. We're pretty sure he's trying to smile!

His name is Mr.Piggy.
Mr. Piggy is wonderful! Looks like a smile to me!

I agree, the Dalmation was smiling at you - even though it startle you if you have never seen a dog do that!