Since giraffes are ruminants, it is very rare for the animal to vomit and, in the very rare instances that they do regurgitate food out of their mouths, it will still be different from vomiting. Questions about the way giraffes vomit spark some curious interest given that the animals have very long necks. However, due to the unique structure of its digestive system, it is almost impossible for giraffes to vomit in the way as some people imagine it to be.
Like most ruminants, the stomach of giraffes have four chambers where the grass are broken down by bacteria. When ruminants graze, the grass pass through three chambers before it gets to the main chamber or stomach of the animal called the rumen. Ruminants voluntarily regurgitate grass from the rumen to chew the grass further in a process called "chewing cud."
When ruminants "vomit" food, it does so by bypassing the third chamber and the contents of the rumen goes into the first and second chamber. The process of vomiting in giraffes often ends either in the first or second chambers and the food very rarely goes up and out of the mouth.
Also called internal vomiting, this phenomenon was shown in a study conducted on sheep, which was published in the American Journal of Veterinary Research in 1981. In the study, sheep were administered with apomorphine to cause acidification in the rumen to induce vomiting. Contents of the stomach chambers of the sheep were merely expelled into the another chamber and no vomit was expelled out of their mouths.