Fur-tunately broccoli is healthy as an addition to their nutritious dog food or as a rare treat, provided you offer a balanced diet. Being a green vegetable, broccoli contains nutrients, is low in fat and packed with essential vitamins and minerals to keep them healthy and strong and boost their immune system. Dogs Need Their Daily Minerals and Vitamins too! Broccoli is an excellent source of the following: dietary fiber pantothenic acid vitamin B6 vitamin E manganese phosphorus choline vitamin B1 vitamin A potassium copper. magnesium omega-3 fatty acids protein zinc calcium iron niacin selenium