If the dog is underage, infection with parvovirus, coronavirus, etc. will cause the dog to vomit and lose appetite. You can do a parvovirus and coronavirus antigen test. If the diagnosis is confirmed, timely treatment is required; if the dog suffers from acute gastritis, vomiting will Frequent episodes can also cause the dog to lose appetite, and some may vomit blood. If the dog is severely dehydrated, infusion treatment is required; if the dog still has abdominal pain, it may be caused by pancreatitis, and symptomatic treatment can be carried out after examination and diagnosis.