Hill's nutritionists and veterinarians developed Prescription Diet l/d, clinical nutrition to support liver health and help protect vital liver function. How it helps: Helps reduce liver workload allowing liver tissue to regenerate Helps avoid nutrient deficiencies & excesses related to the liver Immune system support, critical for dogs with compromised livers How it works: Controlled levels of highly digestible protein Low copper to minimize accumulation in the liver Clinically proven antioxidants to support immune function, formulated to promote healing