At my wits end with my cat...

Are both of them "fixed?" And how old is Spike? Sounds like he is still a kitten.

He sounds like a normal "teenage" kitty to me (did you get Kitten as an adult? If so, I know that having a kitten is a huge adjustment!). How old is he now? How old was he when he was neutered (note: boys are neutered, girls are spayed )? Do you exercise him at all--fishing pole type toys or a laser pointer? It just sounds like he's bored and needs more exercise and stimulation. Maybe harness training him and taking him for walks would help. If it's at all possible, getting him a young friend (an active kitty around his age or a bit younger) would probably be helpful. . .older cats are just so boring and cranky (in his opinion, lol), and it would help him burn off his excess energy.

But I really do think that if you get a Da Bird (or other brand of fishing pole toy) and/or a laser pointer and run him until he's worn out, and do it twice a day, that will help immensely.

No need to buy expensive fishing pole toys if you are willing to dangle a ribbon, etc. Of course the fishing pole toys are more convenient for you. But yes. Play with that cat; tire him out. A tired cat is a well-behaved cat. I know they say that about dogs, but it's true for cats too.

I almost wonder whether the vet might have missed one of his... er... bits when he was neutered. He seems to be acting like an intact tomcat more than anything else; that, and a young, active half-grown cat.

Yea, it sounds like he might not have been erm, fixed properly, so I would take him back in for a check-up.

Screams don't do anything. Try the following for discipline:
hissing
blow air on his face

Your Spike is a hyperactive teenager. I've had quite a few of those and it takes time and patience. They do settle down.

Its still reall early yet since he got neutered so not all the hormones are out of his system yet but also hes still just a baby. Well not a baby but basically a teenager, its like a human going thru a stage that is crazy obnoxious. I have two that are 4 mths old going thru the same basic stage. The worst is the curtain climbing. Honestly the only advice I have to be deligent in your discipline and making sure he learns the rules. Like if you dont want him to bite then every single time he does make sure you hiss at him or tell him no every single time. And it needs to be both 'parents'. You cant keep doing it and then have your dh rubbing his belly rough housing with him letting him bite or scratch. It will completely eliminate any discipline you put out. Patience is the best thing you will have. You just need to keep working with him and being patient because eventually the stage will end.

He'll settle down eventually. With some cats it takes until they're two or so before they're past the "terror" stage. A laser pointer or thrown ping pong ball will work wonders tiring him out without exhausting you. Even just throwing a newspaper on the floor for him to skid around on, hide under, etc.. will keep him occupied for a while.

I have a kitty like Spike and it can be very frustrating at times. You have to be VERY involved in playtime with him. If he starts playing with your other cat too roughly, divert his attention and play with him using a wand toy or a laser pointer. Find some small toys (small furry mice or small balls) that you can toss around, he can chase and then you can repeat. I use small rainbow furry mice that have a little rattle inside them. My guy doesn't "fetch" per say, but he loves it when I throw them and then he gets to chase them. The big thing is divert, divert, divert and play, play, play. If you don't have a semi-tall cat tree/condo, I'd invest in one or make one for him, too. That'll give him vertical space to climb, run up, and play on.

Unfortunately, your guy is normal and it just takes lots of time, patience, and deep breaths to wait for him to grow up a bit.

It really takes a few months after getting him fixed for the sexual behavior to stop...Hes still a kitten and kittens play rough. redirecting him when he gets to rough with your other cat helps..Cats can't and don't understand disapline..No hollering and screaming just redirect remove him from the room gently..

Totally, hyper teen kitty. What I'd call a catten.

Hissing helps. So does pulling away and totally ignoring him. You could carry a water pistol and squirt him (one of those cheap, small ones, please, the ones that just kind of spit water--no Super Soakers!).

But do have the vet check to make sure the neutering was done right. Some cats have undescended testicles, and those can be missed on the neutering, and of course still be sending out the tomcat hormones after the neutering. Maybe you can talk to the vet who did the neutering to see if he remembers whether he got both of 'em. I'm not sure, but I think they can tell by feel if a neutered cat isn't as neutered as they thought...

Anyway, good luck; give it some time; and make it absolutely clear that you do NOT like it when he gets too rough.

I know how you feel since I have 2 cats that did not get along for a while, and one was being abusive. There are different reasons why cats don't get along and we will never understand them all. I had a jealous cat that would attack the other from getting any attention from me. I am very careful about how to punish a cat since it's important to realize that their brains work differently than ours, so we can't think about how we would punish a human child and apply it to a cat. I'm no expert but in my experience spraying a cat with water, yelling at a cat, or doing anything to frighten a cat will not work and will probably make your situation worse. Instead try to look for ways to positively reinforce good behavior. This is what I did to rectify my problem.

When the cat does something bad, like attacking the other cat, I IMMEDIATELY put him in time out (I put him in the bathroom). I do not yell, speak, hit, I don't grab him violently, I just put him in there and close the door. After about 10-15 minutes i let him out. The reason time out works so well is it's boring, and cats don't like to be bored. Furthermore you are performing the action immediately following the bad behavior, allowing the cat to realize "when I do this bad thing, i'm immediately taken to a room where i'm bored out of my mind and there is no more fun". Cats are very intelligent and they systematically figure out how to avoid things they don't enjoy, they also figure out how to find things that bring them enjoyment. The problem with this negative reinforcement, as with all negative reinforcement is, you are not always there to keep it up, and yes the cat will figure this out. Cats are smart enough to figure out "if I do this bad thing in front of my owner, I get punished, so I have to do it without him knowing".

So let's look at the other side of it. Positive reinforcement:
After a few times in time out, my cat showed a good amount of improvement in behavior. Eventually I watched him walk up to the other cat and was being nice to him, and grooming him. I immediately said "good boy", got up and scratched his head. Every time I see him being nice to his brother, I do everything in my power to give him positive reinforcement. Now I have gotten to a point where sometimes they will even lay next to each other and sleep.

In your case it sounds like you have a hyperactive cat. I am a big believer in the basic fishing pole with a feather on the end of it toy, this is the only toy I have seen that is just completely irresistable. When I pull it out of the closet, my cats go nuts. If they even hear the closet door open, they run into the hallway to see whats going on. I make sure I play with both cats together, letting them work together to catch the feather. I run it around and I let them catch it here and there, and I make sure they both get turns catching it (which supports their instinctual behavior to hunt). I also make sure to have one on one time with each of the cats, usually when I am training them. The best way to get a cat to be good is to tire him out, and that's what I do. When we get done playing, you see 2 cats cow tip right over and lay down, that is a happy cat. Their minds for the most part need stimulation, their brains are wired for living in the wild where action is around every corner, now they are in the safety of our quiet homes, we need to give them time to get the animal out of them. I know it seems impossible but I remember being where you are with this one cat I have, he never tried to rape the other but would attack and bite him. I still have a lot of work to do but the progress we have made is amazing.

One last thing I tell everyone. Treat your cat is if he/she was intelligent, because he is. Most cat owners wonder why their cats don't respond to them, they call their name and they get ignored. Because from the start the owner treated the cat like an idiot, and never bothered to stimulate their cat. I can tell you that right now I can call one of my cats names, and they will respond immediately. I can tell them to sit and they do it, if they are about to do something wrong i can say "don't do it" and yes they pull away. The reason for this is they have been treated as intelligent beings from the start. They have learned from me, and I have learned much from them.