So I take my female cat to the vet to get the horrible open sore she has (as a result of a fight with our new cat) checked out. She’ll be fine but while I’m there, I mention to the vet how AGGRESSIVE this new little male cat is and that he’s terrorizing the household. She mentions that there is a medication that contains female cat progesterone that they use, for among other things, curbing male cat agression. Now my neutered male cat not only has the indignity of being fixed, he’s now on female hormones. But, if I could get him fitted out with a little gold lame dress and some heels… 
Actually, hope it works and makes him stop beating the other two up!
Bunnygirl,
I have two cats and two dogs and in both cases it is the females that are more aggressive. Actually, assertive would be a better word. The male dog and cat clean and nurture the females. When the females have had enough “pampering” they either swipe or nip at the males and walk away. My sister thinks this behavior echoes that of my husband and me, I think I should be offended!