I've always put veggies in my dog's food - carrots, green beans and potatoes. Then I bought a dog food with the brand name "Merrick." It was great food for her. They have alot of flavors and they loved it. They never had a problem. But if they were on an antibiotic and got constipated, I always gave them some canned pumpkin. Very, very little at a time because it could throw them the other way completely. Once they are not constipated any more, stop the pumpkin.