Hello!! And Welcome to YT!! My Riley is about 5 1/2 months now... he has been losing teeth the past few weeks, and I have noticed in the past week or so that he is starting to lose his puppy breath.
Fortunately he enjoys having his teeth brushed. I was doing it once a day but started slacking a little and that is when I noticed it was starting to be not so fresh. I started brushing daily, again and have had No Problems.