Baby bottle rot is severe tooth decay that can occur in young children from sugary liquids consumed from bottles. It is caused by germs and sugar combining on teeth. Signs include pain, bad breath, and discolored teeth. Untreated baby bottle rot can lead to infection of adult teeth and problems with eating, talking, and pain. Parents can prevent it by cleaning teeth after feedings, avoiding bottles with sugar, and switching to sippy cups once teeth emerge. A dentist can treat existing decay.