Hill's Prescription Diet j/d Joint Care Chicken Dry Cat Food has been clinically proven to improve activity levels in cats struggling with mobility issues in 28 days. It helps maintain cartilage cover inside the joints and also lean muscle mass thanks to high levels of DHA (a special omega-3 fatty acid from fish oil) and glucosamine and chondroitin sulphate from natural sources. It is also a complete and balanced food that provides for all of a cat's nutrient needs, while supporting a healthy immune system.