Observe the physical condition of the dog. If symptoms such as poor mental health, vomiting, high fever, etc. appear, it should be a disease in the body. It is recommended that the owner send the dog to the pet hospital for careful examination to avoid deterioration of the dog's condition. If the dog is in a normal state of mind, but just refuses to eat and has diarrhea, it should be a sign of a cold or parasites in the body. Check first to see if there is a cold before deworming the dog internally and externally.