Paintballs are little bullets of paint used for shooting games. They can be dangerous to dogs that are hit or to dogs that ingest the paint balls.
Several dogs have lost their eyes from being shot in the face.
To keep your dog safe, supervise your dog and don't let him run free. If you have paint balls in your home, safely store them away from your pet.
For more information about the danger of paint balls, read Paint Ball Dangers and Toxicities