Regarding whether catnip or silver vine leaf sticks are safe for cats, we're here to tell you that all natural and unprocessed sticks made by trustworthy companies are indeed harmless for felines everywhere. Every cat chew stick included in Petside's product selection has been rigorously tested to guarantee compatibility with cats' teeth and digestive system. It's when you start handing over your cash to unreliable brands that problems start to arise.