Is it true that gum is bad for dogs?

Not all gum is bad for dogs, but sugarless gums that contain xylitol (a cavity prevention ingredient) can be toxic to dogs. Xylitol can cause a sudden drop in blood sugar, leading to weakness and collapse. However, it can also cause acute liver failure. If your dog eats gum or sugar-free candy that contains xylitol, it is important to contact your veterinarian right away.