Rat poison is a chemical called warfarin. It makes the blood very thin so that it can’t clot. An animal usually dies from rat poison because it bleeds to death internally. So even if your dog is not showing external signs, it could still be bleeding to death inside. The treatment for warfarin poisoning can include vomiting, but often includes administration of a medicine that makes the blood thicker so that the internal bleeding stops. Only a vet can administer this lifesaving medication. So if you ever suspect that your dog ate rat poison, you should bring it to the vet immediately!