Our labrador retriever used to have bad doggy breath, too. To somehow lessen the smell, I regularly take him to the groomer to have his teeth brushed. However, when I am too busy at work, I just make sure that he has chew bones that clean teeth and freshen breath. You can try using Dentastix by Pedigree. They have different kinds for different sizes of dogs. They are very affordable, too. Here's the link, so you can check it out.
We have the same issue with our older dog. She is very loving and always wants to cuddle and get close to you but her breath is so bad it's hard to. We also give her bones and rawhide to help. I did buy the Dentastix and they do help!
If your still having the problem, I would take him to the vet or a groomer where they can brush his teeth. I know that's sometimes easier said then done but it's worth a try !