for our cats what helps is CBD oil. it's specifically meant for calming animals, and comes in various concentrations, so you can adjust them to an animal's body weight. should have sensible concentrations and price/performance up to medium dogs, but of course light cats make it much easier to stretch a vial. it also comes in at the very least natural oil or salmon oil, depends on the animal which they like better. our cats don't like the salmon very much.