Purina One +Plus Hairball formula Nutural and Fiber Nutrition See results in your cat by combining nature and research in Purina ONE +PLUS Hairball Formula adult dry cat food. This easily digestible recipe includes a SmartBlend of high-quality ingredients that get to work in your cat. Driven by nature the hairball control cat food uses real chicken as the #1 ingredient and offers 38 grams of protein per cup helping to support her strong muscles including a healthy heart. A natural fiber-rich blend helps minimize and control hairballs and four antioxidant sources in this hairball cat food help support her strong immune system.