I posted on your other thread about Clomicalm but in case you missed it, I can tell you that I've had no problems whatsoever w/it. It works wonders for behavior problems. I have 4 cats on it currently because they would be pee cats if not for Clomicalm. No personality changes, no physical side effects and it began working immediately. You have to trust your instincts, though, and if you feel it isn't the route you want to take, then the suggestions that other PTers have posted might work for you. Good luck whichever way you decide to go. We want Paddy to be happy and healthy.