You folks seem far more informed and experienced in the pet/cat department; however, I've never heard of Prozac for a cat!! While I haven't studied animals, I have studied psychotropic drugs extensively. My concern would be that the cat might get something called "Serotonin Syndrome". It's akin to an overdose of Prozac and in humans can cause exteme headaches, nausea, nervousness, inability to sleep -- even death!! If vets are recommending it -- then it must be safe. But, I would still be very careful not to give a a cat too much! They are -- obviously -- much smaller than humans and I would assume the dosage of Prozac they get would be minimal, to say the least. Just my 2 cents here.