It needs to be a legal requirement to list xylitol on the label. Along with anything else known to be severely toxic to pets.

To help people out, xylitol is most commonly found in sugar free peanut butter and sugar free gum. It's also found in some toiletries, in many oral care products, and in other sugar free products (candy, cake mixes, ice cream, chocolate, etc). It's apparently very common in sugar free ketchup.

Basically, check the label on anything sugar free and if in doubt, be careful to keep it away from dogs.

If the label says "sugar alcohols," assume xylitol is in there.

Cats are NOT affected by xylitol. Just dogs.