According to The Daily Puppy, dogs can eat sugar in moderation. While giving dogs sugary snacks every so often is fine, too much sugar can cause issues, inclusing cavities, obesity and diabetes.
Fruit is typically the best type of sweet snack to give dogs because the sugar contained in fruit is naturally occurring. Peanut butter is another sweet treat that is safe to give to dogs. Dogs should never have foods sweetened with xylitol, according to WebMD. Xylitol is often found in diet foods, such as sugar-free candy, and can cause issues such as vomiting, lethargy and liver failure. Dogs should also never consume chocolate.