It is inevitable that your dog will experience an upset stomach at some point. Usually, this isn’t a cause for concern, and it should resolve itself within a day or two. Learning how to settle a dog’s stomach will help to alleviate the symptoms faster to make your pup comfortable again. Read the full guide here: https://topdogtips.com/how-to-settle-a-dogs-stomach/
If your dog shows signs of an upset stomach on a regular basis, you should seek the advice of your veterinarian. He may have a food allergy or an underlying medical condition. If the upset stomach is accompanied by other symptoms, like blood in the vomit or stool, you should call your veterinarian as soon as possible.
"While your dog is fasting, ensure access to cool fresh water. He needs to stay hydrated, but don’t let him drink a lot of water at once time. Like us, too much water too quickly could cause your dog to vomit."