Pepto Bismol can be used on dogs in small quantities, according to the Jefferson Veterinary Clinic. The exact dosage depends on the dog's weight.
One teaspoon of the medication should be given for every 20 pounds that the dog weighs. Pepto Bismol is used to treat diarrhea in humans and dogs. It should never be given to cats, notes the Jefferson Veterinary Clinic. If the symptoms in the dog persists for more than 24 hours or the dog shows an adverse reaction to the medication, a vet should be consulted as soon as possible. The medication should not be given if the dog has ingested a toxic substance.