How old is the dog? Mandy did this as a puppy when she got a bladder infection/ teething.
Never figured out what one it was but for about 2 weeks her mouth was constantly soaked. I thought stress teething but then realized she had an infection. Stopped once we had all that cleared up so not sure
I am with Katz, a vet visit is in order, Is it a boy? I mean that sound silly to ask, but some males if there is a female in the area that is in season, the excitement can cause them to do that. On the other hand, going to the vet would be able to rule out an ear infection or anything else that may cause him to be dizzy which would cause him to drool from nausia. I would go to the vet.
I agree with the others, I feel it would be best to see a vet. I have never heard of this being a typical poodle thing. We have one poodle who drools excessively during car rides, but that is because she feels sick to her stomach, so I would be afraid that something is making your dog feel ill.