SAS- I am no vet, but Ibelieve your vet has it wrong. 5 mg is very, very, very common a dose to start with, though I know my sister in law is on 2.5 to begin. Her cats are behemoths, by the way.

I don't know what my cats weigh, but it is closer to 8-9 pounds. I increased my sonic boy up to 10 mg a day (5 mg in the am, and 5 mg in the pm) and it has worked very very well. I didn't even go back in to see him, I just upped it as I know someone that did the same, no problem.

I don't notice a darn thing with appetite (heck, Sonic eats a ton!) and noticed what might have been some sleepiness that very first day. Nothing since.

I wouldn't mess around with 1 mg. I would go to 2.5 and see what happens.