Some causes of a dog throwing up include poisoning, parasites such as giardia, intolerance of certain foods, heatstroke, bloating, or dislocation of the dog's stomach, according to PetMD. A dog who ingests a poison, such as any part of a castor bean plant, not only vomits but suffers kidney failure and a collapse of its central nervous system. This can lead to death.
A dog who ingests the giardia parasite may have no symptoms, but if it does, vomiting is often accompanied by weight loss, diarrhea and an overall malaise, says the Companion Animal Parasite Council. In some cases, giardiasis leads to death. It can be prevented by making sure the dog has clean drinking water, and disposing of the dog's feces so that the infection doesn't spread.
Heat stroke or hyperthermia in dogs presents with many symptoms, one of which is vomiting, including vomiting blood, says PetMD. If the hyperthermia is the result of the dog being in a hot environment, it needs to be removed and its body temperature returned to normal. This means spraying or immersing the dog in cool, but not cold, water or wrapping it in towels soaked in cool water. The treatment should continue until the dog's temperature drops to about 103 degrees Fahrenheit.