Xylitol acts quickly in dogs and cats leading to a severe drop in blood sugar, vomiting and eventually liver failure. That can all happen in just a matter of days. Other symptoms of xylitol poisoning include disorientation, as if your pet is in a stupor, and seizures. If that happens, take your pet to the vet right away. Be sure to take the product packaging with you because the ingredient information can help your vet track the source of the poison and better help them treat your pet.