Worth a try but no effect on my Collie
Tried this for many hours with my nervous-aggressive Collie but made absolutely no difference whatsoever (which I have heard since from other folk). He is now on Yucalm (Behaviourist recommendation) other option was Zylkene (Vet rec) and, tablets fed twice a day, noticed a difference immediately but brilliantly settled now, six months later. I'd try tablets rather than pheromones if I were you.