Xylitol is a naturally occurring alcohol found in most plant material, including many fruits and vegetables. It is extracted from birch wood to make medicine. Xylitol is widely used as a sugar substitute and in "sugar-free" chewing gums, mints, and other candies. However, sorbitol is the most commonly used sweetener in sugarless gums because it is less expensive than xylitol and easier to make into commercial products. As a medicine, xylitol is used to prevent middle ear infections (otitis media) in young children, and as a sugar substitute for people with diabetes. Xylitol is added to some chewing gums and other oral care products to prevent tooth decay and dry mouth. Xylitol is sometimes included in tube feeding formulas as a source of energy. Dog owners should know that xylitol can be toxic to dogs, even when the relatively small amounts from candies are eaten. If your dog eats a product that contains xylitol, it is important to take the dog to a veterinarian immediately. How does it work? Xylitol tastes sweet but, unlike sugar, it is not converted in the mouth to acids that cause tooth decay. It reduces levels of decay-causing bacteria in saliva and also acts against some bacteria that cause ear infections.