A dog's loose stools and eventual diarrhea may be caused by internal parasites, improper diet, indigestion, bacterial infection, viral infection, etc. First, the dog needs to be fasted and water-free, and then fed with probiotics to regulate the gastrointestinal tract. Observe for two days to see if there is improvement. If not, it is best to send it to the pet hospital for examination in time to confirm the cause and then carry out targeted treatment.