Q. My dog is puking is pepto ok for him
A. Technically you can (1 teaspoon per 5 pounds) but do you know what caused the tummy troubles? If your dog ate something bad, it will remove it from its system by vomiting, if that is the case, you want it to vomit it up. It is also not suitable for all dogs, some have allergies to it, do not substitute another brand as ingredients may change, and it can interact with meds if you dog is on any.
Instead I would try fasting him for 24 hours. Water only. Then start him on a bland diet. Take some chicken or ground beef (unseasoned) and boil it until cooked. Use the water to make some plain white rice and only feed him this until the vomiting stops. Keep him on this for a day or so and slowly re-introduce his food over the next couple days, weaning him off the bland diet. If his condition gets worse or he stops drinking then go to a vet