Probiotics can be helpful for dogs suffering from diarrhea, especially diarrhea caused by stomach upset from switching foods abruptly, diarrhea caused by stress or anxiety, and diarrhea that occurs after using antibiotics. However, it’s important to see a veterinarian to find out what is causing your dog’s diarrhea, as probiotics alone cannot always resolve diarrhea, and your dog may need further tests or treatment. Always talk to your veterinarian before starting any supplement, including probiotics.