My ds is 23 months and dribbles a lot! He finished teething at 18 months so I know hat's not it - but when he's ill it's uncontrollable. He had a cold recently and it finished about a week ago, and he seems to have a mild sore throat and cough, bland the drool is pouring out of his mouth to the extent that last night we had to change his sheets three times within an hour of him going to bed because he'd dribbled so much they were soaking. Today he has had 6 bibs, which are saturated within half an hour, as are his clothes. Constantly finding pools of dribble everywhere. It's not quite this bad when he's in full health but, even so, it seems excessive.
He was born with an extremely severe dual tongue tie - the bottom jaw one was snipped at 2 days, the upper jaw one can't be snipped. He has a dummy but limited use - it is better when he doesn't have a dummy, but not drastically so. He also still mostly drinks from bottles - he can drink from sippy cups but will only drink milk from a bottle and he drinks milk about 80% of the time. I guess these are all contributing factors, but I'm also wondering how much I should be worried.