Because dogs with skin conditions or food sensitivities also need an occasional treat, at Hill's, nutritionists and veterinarians have developed special treats for dogs on Prescription Diet® d/d® Canine, Prescription Diet® z/d® Canine, Prescription Diet® i/d® Canine, Prescription Diet® i/d® Sensitive Canine And Prescription Diet® Derm Defense dog foods. These treats are formulated to promote a urinary environment that reduces the risk of developing struvite & calcium oxalate crystals when fed with a compatible S+OXSHIELDT™ food