Considered the most nutrient-dense berries, blueberries are chock full of antioxidants, fiber, vitamins, minerals and phytochemicals (naturally occurring chemical compounds found in plants). Blueberries provide the same benefits for your pup’s body that they give yours. Studies show that adding antioxidants to a dog’s diet reduces the effects of brain aging. Along with other beneficial properties, these berries contain a substance called anti-adhesives that show a significant reduction in the adhesion of E. coli bacteria and can be beneficial in preventing urinary tract infections in dogs.