A dog that is diarrhea but very lively may be caused by improper diet, indigestion, internal parasites, etc. You can give your dog some probiotics to help regulate its intestines and promote digestion. You must also give it on time. For dog deworming, it is best to feed the dog some light and easy-to-digest food, and then observe it for two days to see if there is improvement. If there is no improvement, it is best to take the dog to the pet hospital for examination.