Dogs vomiting yellow water with foam on an empty stomach may be caused by food poisoning, gastritis, canine parvovirus, pancreatitis or abnormal kidney function. They need to go to the hospital for examination in time to avoid delaying the condition. At ordinary times, you should pay attention to keeping your dog on a leash when walking your dog, and do not let your dog eat randomly outside. Try to eat a lighter diet, maintain adequate and clean water, and deworm your dog regularly to avoid parasites in the body.