This is a pretty common problem with my 4 labs,,I got this advice from a friend of mine and it really works,,,,and best of all it is cheap !!!

The reason (especially) labs smell, is because with thier dense coat and thier frequent visits with water!! the coat tends to be a breeding ground for bacteria,but as we all know bathing a lab too much breaks down the water repellent oil found in thier coat anyway,,,,,,,so here is the solution,,,,,Rinse them off with regular tap water and then completely drench them in a solution of 2 pints vinegar mixed with 2 gallons of water,,,I promise they wont smell like vinegar!! DO NOT rinse them off after you have applied the water/vinegar solution,, For a quick fix you can mix (about half and half) a spray bottle full of water and original forumula Listerine,, spray them with it and then rub it in!!

Hope this helps, it will work ,,trust me I have 4 labs that love water and then LOVE to crash in my house!! So they HAVE to smell good!