M.H.
The fever and fussiness could be a possible infection of some kind. Could be post nasal drip or a sinus infection. Both can cause some nasty breath.
My baby is 15 months. He only has 4 teeth (we are late bloomers at our house). Anyways, the past few days I have noticed that he has bad breath. We brush his teeth several times a day b/c he loves to chew on his toothbrush. I think he is cutting teeth b/c he was extremely fussy last night (very uncommon for him) and was running a fever. What could be the cause of the bad breath?
The fever and fussiness could be a possible infection of some kind. Could be post nasal drip or a sinus infection. Both can cause some nasty breath.
Post-nasal drip and/or throat infections can make the breath smell nasty. If you are able to look, you may see swollen tonsils.
My toddler had something stuck in her nose, we had no idea!
T.,
Are you still nursing? If mom eats garlic and onions, the nursing child will smell like garlic and onions!
My son's bad breath was due to his reflux, it was very metallic/acidic and funky ewww!
It sounds like it's coming from his tummy, not his teeth. Look to what he's eating.
It's not normal for babies to have bad breath and is usually a sign of illness somewhere or food they ate. Maybe have him checked out at the doctor for throat, ears, nose, stomach issues, etc.
Look at his tonsils. I can't remember how old my daughter was when I discovered the cause of her chronic bad breath was massive tonsil stones in both tonsils. One day I looked in her mouth and saw these huge white things in the back of her throat and went what the heck? I spent months squeezing her tonsils out. I think she was three or younger.