For the Nutritional Management of Obese Prone and Slightly Overweight Dogs and Dogs with Fiber Responsive Diseases. Prescription Diet* Canine w/d* was formulated specifically to help manage dogs who are prone to gaining weight. Prescription Diet* Canine w/d* is also useful as a nutritional aid for dogs with fiber responsive diseases such as diabetes mellitus, colitis, diarrhoea, constipation and struvite urolithiasis management in obese dogs.