An owner can treat his dog's upset stomach by not feeding the dog for 12 hours, giving the dog bland foods when he resumes feeding, and adding a spoonful of ginger root, cottage cheese or canned pumpkin to the dog's food. If the dog eats grass, allow this, says VetInfo.
Additionally, the owner should encourage the dog to drink water, as dehydration is a risk with stomach upset. The owner may consider adding some Gatorade or Pedialyte to the dog's water to replenish fluids dog's system is losing. If the upset is prolonged, or if the vomit or stool contains blood, VetInfo advises consulting a veterinarian.