The most important thing to remember about first aid is that it's only FIRST aid. The dog still needs to be rushed to the vet as quickly as possible. Still, there are a few things you can do. Some human first aid can be applied to dogs. A dog choking from a bone or other obstruction in its throat may respond to the Heimlich maneuver. Direct pressure or a tourniquet can be used to stop bleeding. A dog who's been hit by a car will be in shock. Cover it with a blanket and move it very carefully on the way to the vet. There's one major difference between applying first aid to dogs versus people: a person's not likely to bite you. Any dog, no matter how friendly, may snap if it's blinded by pain. Before taking any action, muzzle the dog with a belt, tie, or strip of cloth. If the situation isn't immediately life threatening, don't do anything except taking the dog to the vet. You don't want to inadvertently do more harm than good.