Most peanut butter that you find at the store is not safe for dogs to consume. The main reason why dogs can't eat normal peanut butter is because it contains a harmful ingredient called xylitol. Xylitol is a sugar alcohol that is often used as a sweetener in many products, including peanut butter. It's perfectly safe for humans to eat, but it's extremely toxic to dogs. Even ingesting a small amount of xylitol can cause your dog to have low blood sugar, which can lead to seizures and even death. So, if you're going to give your dog peanut butter as a treat, make sure it's one that doesn't contain xylitol.