According to Dr. Lori Siracuse-Parker, veterinarain at Oradell Animal Hospital in Paramus, NJ, Pepto-Bismol (bismuth subsalicylate) can be used in some dogs occasionally for an upset stomach/diarrhea. It is also sometimes used by veterinarians to treat certain gastrointestinal illnesses. You should always call your veterinarian before giving any over the counter medication as many are potentially toxic to our pets. You should always contact your veterinarian for an appropriate dose and to make sure there is no contraindication to giving Pepto-Bismol based on your dogs clinical signs, medical history, and other medications your pet may be taking. It is important to know that Pepto-Bismol contains aspirin so it should not be used in dogs that are sensitive to aspirin, those with a history of GI ulcers or bleeding disorders, or in combination with steroids or other non-steroidal medications. To do so could cause a fatal bleeding episode.