Dogs can eat bananas safely in moderation. Bananas are a good occasional treat for dogs as they are rich in potassium, vitamin B6, vitamin C, fiber, and magnesium. However, because bananas contain a high amount of sugar, they should only be fed in small amounts to avoid digestive upset or weight gain. It is best to peel the banana and serve it in appropriate portions based on the size of the dog. Banana peels are not toxic but are hard to digest and could cause digestive blockages, so they should be avoided. Treats like banana should make up no more than 10% of a dog's diet to maintain a balanced nutrition. Puppies and smaller dogs should be given smaller amounts to prevent stomach upset.