Zylkene is a calming supplement for dogs and cats, clinically proven to help your pet feel more at ease during stressful situations. The active ingredient in Zylkene is a milk protein with natural calming properties, so all products are non-medicated and non-drowsy. Use Zylkene Calming Supplement for short-term events, like vet visits or fireworks, and Zylkene Plus for long-term situations such as separation anxiety in cats and dogs. You can also shop by pet type and browse all Zylkene for dogs and all Zylkene for cats.