Baby with bad breath

[fruitscone]

My DC (1) has had foul smelling breath for two days. Prior to yesterday I had never noticed it before. I don't think she is teething. What could be causing this?
Thanks

It can sometimes be a sign of a throat infection or tonsillitis. Any signs of her feeling poorly?

if she has a cold or blocked nose and is breathing though her mouth that might be contributing.

It is foul smelling, not sweetish. No sign of her being otherwise under the weather and no sign of a cold.

My dd had really bad breah when she was diagnosed wih an ear infection, but she did have other symptoms (mainly temperature). Any temperature?

She doesn't feel hot but I will check temperature when she gets up from her nap.