Male aggression behaviour

Hello. I have a 4 year old male cat who was neutered as soon as his testicles were dropped so this has been done for years. He can still be very aggressive towards orher male cats and I caught him on top of my female cat (1year) yesterday. Just wanted to know if it’s normal for neutered cats to still be like this? I’m worried that something wasn’t done right. Or could it be a behavioural issue?

Hello!  When you say that you caught him on top of her - were they mating, or fighting? This could certainly be a behavioural issue; cats do indeed chase and stalk, or fall out with others, both male and female, for reasons that are and aren't to do with sex.   In fact, cats are not as well adapted as we sometimes think for group living.  They can cooperate well in colonies but lack the sophisticated behavioural pack interactions that dogs have.  As a crude generalisation, dogs communicate social unease  with a progression of different body language interactions, obvious to observing humans; cats body language is more subtle.  Cats sometimes appear to ignore / tolerate each other until the moment they decide to fight. Things that are thought to ease tensions between cats including giving each their own food bowl and having a litter tray per cat plus an extra one in your house; ideally, each cat will have a litter tray on their own 'territory.' (Draw a map of your house.  A few times an hour, put a coloured spot where each cat is.  Thus you will be able to define each cats territory.  Crossing the other cats territory eg to get food or water or to go to the toilet, can be extremely stressful for them, so moving beds / water / food around can sometimes make a big difference). Aggressive behaviours between cats can get worse if left to fester, so we would strongly advise reading as much as you can around this and perhaps consulting a qualified feline behaviourist as early as you feel that it is required.  There are some posts that you may appreciate in the blog and Sarah Caney's blog / site, iCatcare, can be invaluable. Best of luck and please do let us know how you get on.