Purina One +Plus Dry Dog Food Joint Health formula, Support your dog's joints and mobility with Purina ONE +Plus Joint Health Formula Natural With Added Vitamins, Minerals and Nutrients adult dry dog food. We select a SmartBlend of high-quality ingredients for premium dog food with 100 percent nutrition and 0 percent fillers. Real chicken is the first ingredient in the high protein dog food that helps support strong muscles, including a healthy heart. Fish oil and glucosamine help support mobility and joint health for dogs, especially for medium- to large-breed or senior dogs. We craft our Purina ONE +Plus kibble dog food in Purina-owned facilities, so you can feel confident about his dog dry food.