Research is being carried out to look at benefits of using Zylkene® over placebo to reduce fear in dogs presenting for veterinary examination. This presentation will review the mechanism of action of α-casozepine, which is the active ingredient of Zylkene. Although the biological action of α-casozepine, anecdotal reports from pet owners and the work of previous studies all support its use, there have been no studies to give evidence of benefit when used as a situational calming agent for veterinary clinic visits. The current research as well as previous studies will be discussed.