Just a quick clarification- wild dogs do not vomit unless there is a health problem. The same goes for domestic dogs. Regurgatation on the other hand is very common in wild canines. The difference is that an animal will usually regurgatate right after eating and it will on consist of undigested food.
Vomiting can occur anytime and consits of partially digested food and bile.
It offten helps to raise their food. If your dog does vomit once or twice you don't need to rush them right off to the vet. In this case pepcid ac and fasting for 24 hours works great.