Aggresive Cat Attacks Strange Cats

one word, a very important one- Neuter!

I've only had three cats in my life, all neutered males, so don't have the experience a lot of others on here have. I keep hearing that neutered males are supposed to be so much more mellow than intact cats. But my first cat, Guard Cat (he was named that for a reason) and one of my current cats were both very aggressive and territorial. Red Cat did finally accept Purdy when I took him in about three years ago, but we had several months of catfights before they settled the issue that Red Cat was top cat. Both continue to chase any other cat they see from the yard and will fight them if they catch them.

I've read the theory proposed by one behaviorist that males neutered later in life may be more inclined than those neutered younger to keep the same territorial and roaming behaviors seen in intact cats. Red Cat was at least age two before he was neutered. So maybe that helps explain it. Or it just may be his individual personality. But I just thought you should know that some neutered cats can still be territorial, too, even if "on average" a neutered cat is less aggressive.