hi there, bad breath
mainly is caused due to bad oral hygiene
and sometimes due to upset GI function.Five year old children are not very keen on brushing their teeth. You need to supervise the brrushing routine morning and before bed time. See that he has no bleeding gums
, cavities or food particles left over in the food, they should be taught to clean their mouth with water after every meal. If he is not consuming well balanced diet of fiber and fruit but mostly subsists of refined food and starch or sweets then also they may have bad breath. A regular bowel movement is also essential for good GI function. Encourage him to gargle with mouth wash liquid of his choice. Get regular checkups done by dentist
. Hope these help. Take care.