Hill's® Prescription Diet® z/d® Low Fat Hydrolyzed Soy Recipe for Canine Food Sensitivities Dry Dog FoodHill's Prescription Diet z d Low Fat Hydrolyzed Soy Recipe for Canine Food Sensitivities Dry Dog Food This Prescription Diet is sold under veterinary supervision. Please check with your veterinarian if this diet is suitable for your pet before purchase. Dogs with recurrent gastrointestinal issues may have a food or fat sensitivity and while they require different nutritional management their signs can be indistinguishable. Hill's Z D Low Fat