Yes, Sprout drools...tons. He still has every single one of his teeth. He's 13 years old and very healthy.
He drools when we say "walkies?"
He drools when we say "byebyes?"
He drools when we say "want some?" for treats (and drools for "treat" too)
He drools when he knows "daddy" (my husband) will be home soon, and will drool for about 20 minutes before he walks in the door.
His is not thick or gooey/slimey though, it's just watery saliva.
I'm not saying there's nothing wrong with your dog (there might be a medical explanation for it). For ours however, it's just the way he is. He drools when he gets excited and it's normal for him. Every dog is different.
Also...he's done it since he was 3 months old (and probably before then, too).
I never questioned it or thought it was weird, but with this post I see that it apparently is "different" LOL