I think I may take him to see the vet actually as nothing is working. I don't think it's his teeth now, maybe it's intestinal He is fine in himself, but something doesn't smell right!
Smell is a good indication; thing is, you noticed it was different, that's why I said maybe get him checked out - different is always a sign of something, usually something simple.
I took Jasper to the vet today and the problem is coming from his lip folds. There is a bit of an infection so he is on antib's for a week and she has shown me how to wash the folds with some diluted hibiscrub. So all is well