Generally, you can give your dog 1-4 tablespoons of plain, canned pumpkin (not pumpkin pie filling) per day. For small dogs, start with 1 tablespoon, for medium dogs try 2 tablespoons, and for large dogs, you can give up to 4 tablespoons. Pumpkin is a good source of fiber and can help with digestive issues such as diarrhea or constipation in dogs. Be sure to consult with your veterinarian before adding pumpkin or any new food to your dog's diet, especially if your dog has any underlying health conditions.