Bad breath in children is most often either food or bad breath. Food halitosis is most commonly caused by abnormal oral odour after eating smelly foods such as onions, garlic, leeks and mutton, and not cleaning the mouth properly.
Rotting bad breath is an odour produced by tartar or food debris embedded in the teeth, which ferments under the action of bacteria, and parents are advised to use dental floss to help clean their mouths.