Hill’s Prescription Diet z/d Hydrolysed Dry Cat Food is specially formulated by nutritionists & veterinarians to help cats with food sensitivities, and is clinical nutrition to help avoid adverse food reactions. Rich in Omega-6 and Omega-3 fatty acids to promote skin health and regeneration. Made with highly hydrolysed proteins that are broken down to avoid detection by the immune system. Formulated without intact animal protein sources. Fortified with Hill’s ActivBiome+ Digestion proprietary blend of prebiotic fibres, clinically shown to rapidly activate the gut microbiome to support digestive health and overall well-being. S+OXSHIELD: Formulated to promote a urinary environment that reduces the risk of developing struvite and calcium oxalate crystals. These characteristics make Hill's Prescription Diet z/d Dry Cat Food a useful nutritional aid for cats with adverse food reactions or certain gastrointestinal disorders. S+OXSHIELD: Formulated to promote a urinary environment that reduces the risk of developing struvite and calcium oxalate crystals.