My cat is viciously attacking his litter mate

This is quite lengthy. But if you decide to read and help , your awesome !
Got both of theses cats when they were 6 weeks old . They are 1 and half right now and they are litter buds . Jay ( the black and white cat) is a very passive cat . He is so innocent, I have seen him get attacked by other cats and he just sits there and curls up. Never seen him hiss in my life . Rudy on the other hand can get very aggressive. He started this while young when I give him treats he will visiously hiss . He also hisses at house guests . But he recently started attacking his brother . One day I was letting jay chill in the yard outside. Then after awhile I let Rudy go out there with him . Rudy arched his back puffed his tale and started screaming (loud high pitch cat noises) . Then when they both went inside he started attacking his brother while his tale is puffed and while hissing . Poor jay just runs and curls up . Jay never done anything to Rudy. he first attacked him like 3 months ago we nurtured both of them and decided to keep indoors cats . Most of the time they are okay with each other but Rudy acts up sometimes and it seems to happen for a reason.

3 days ago this annoying family friend came over . She decided to go to my room to pet jay , rudy was behind the curtains. When Rudy noticed her he hissed at her. When that happens my brother told her to leave the room now but she didn't do it Rudy hissed again the bitch hit him in the head . Rudy started going after . She started screaming and we kept telling her to stfu since Rudy hates loud noises and it's only going to make it worse. After we got her out, Rudy started without mercy attacking his brother while making those loud cat screams . Poor jay was just sitin there. I separated them and Rudy eventually loosened up .but yesterday and today Rudy will puff up his tale and attack jay out of the blue. It just happens this morning I have both of them separated . Every time I let Rudy out of the room to see if he calm down, He will just run up on his brother and attack him . Rudy can be a sweet cat but he needs to stop attacking jay. Any suggestions?

Are they neutered?

Rudy's aggression could also be triggered by an illness or injury. Cats can be pretty good at trying to cover this up. Has he recently been checked over by a vet?

They both got neutered like 2 months ago

I am sorry to hear this.

In the incident that you mention that happened in the room with the family friend it sounds like "redirected aggression". A cat gets upset by something and takes it out on a different thing (cat or human). In your case Jay.

Do you have ferals that possibly go in your yard? The situation in the yard could be redirected aggression. But I don't have enough evidence.

I worry that Jay might lack confidence. And because of that is more vulnerable to being attacked.

How do Jay and Rudy walk around? Tail high or slinky? Does Jay avoid Rudy at all? Does Jay or Rudy avoid any areas of the house? Where do they hang out? Up high in cat trees? Or under beds? Do they eat near each other or do they eat at staggered times etc?

I would suggest doing a few things.

I would work to build their confidence. We do that through play, food, height and love. If possible I would really like you to step up playing with both cats (not together but if one joins in and they both play that is fine but ideally play with them separate and all over the house). After a good play session feed either treats or a meal. Also try to feed them near each other. Also try to get them up in the world, on cat trees, on beds, on the back of couches, etc. And finally try to give them love and get them to purr but only if you are not putting yourself at risk of being scratched or bitten. We want them to feel confident and secure and we want them to know they own this territory. If we build their confidence then we should see less confrontations as a confident cat is less likely to attack or be attacked.

I wonder if Rudy is feeling territorially insecure because of ferals. The above work to build confidence should lessen that feeling if it is in fact the case but there are some other things we could do.

Finally, cats can take on our stress and emotions. Please try to be as calm and confident as possible around the cats. The more calm and confident we are the more calm and confident they can be.

Any additional information you can share could be helpful so please feel free to let me know the situations and please feel free to ask anything anytime. I am happy to try to help improve the situation.

CalicosRSpecial I really appreciate you writing all of that ! . Let me first answer your questions. I noticed you asked about strays a lot . Yes there are a lot of wild cats outside and when ever I see jay and Rudy run from one to another there is always a cat outside. But how does that affect rudys behaviour ?

As for my cats I do as best as I can to keep them happy and they seem to be relaxed . They walk around with their tail up and don't really hide . They hangout on top of beds they usually sleep on my bed even tho they have beds of their own lol. Jay seems to be confident but he is very passive . Their was a time where we let a stray pregnant cat in our house to feed it reall quick jay walked up to it to sniff its butt the cat hiss and swiped at him he just sat there curled up. Jay wants to go outside and explore but when it comes to being confronted he doesn't hiss or attack back . But I wouldn't say he is a scared cat . Cause he never hides and he likes house guests. And they do everything together .

They eat together , play together every day and seem to love each other's company. But thinking about it now, ever since we moved here 5 months ago both of them have been acting different. And Rudy gets aggressive after he goes outside . One day after I brought him back in he was hissing at jay and out of nowhere attacked my leg. And boi he left a mark . But since we stopped talking them out since it's not safe for them here unlike the other house , Rudy stopped attacking and everything was ight . But after what happened with that lady that hit him in the head he got triggered again . But this time he won't stop it's been three days . And during these days it's on and off . This morning as soon as I woke up he started attacking jay . He is in a room rn and I been playing and hangout with them alternating. . Jay right now is very scared of Rudy and I want them to go back to normal

I have to agree with @CalicosRSpecial  and say that it sounds like Rudy is insecure/lacks confidence. 

Moving probably set him off because his whole world changed suddenly and that woman didn't help any. Insecure cats take a lot of comfort from routine and stability in their territory. In moving he lost his home and security of known and defined territory. If he can see and smell neighborhood cats that upsets him because he is worried about them being in his new territory. Having a stranger go after him unsettled him and his view of where he fits in the world. Some cats react by peeing and marking everything to claim it as theirs. But Rudy has gone a different route of lashing out in frustration at those around him.

At least that is what I am reading in the situation.

One step you can take is to make it so he can't see those other cats. If you have low windows put something over them to block his view. Shoo them away if you see them around. Use a yard deodorizer to remove the scent of other cats near windows or doors.

Other step would be adding a cat tree (or two or one with two high perches so both can enjoy) so he has something purely his that acts as a scent anchor. Something so that when he walks into the room he has something the smells like him and helps him have a physical "mine" feeling. It also increase their height which helps cats feel more secure in a world where they are typically at knee level. You could also do the cat walkway shelf units up a wall or a window perch (near a window with trees or bushes to hide other cats from view) to achieve the same effect without losing floor space. I just got one from a company called Kitty Mansion that is great or you can build your own.

Try playing with him more frequently and getting some of that nervous energy out. A play session when you wake up and before bed will hopefully help him work out that aggression and feel more stable at the same time with the routine. You want to play with him until he is panting, let him rest, then go again. Wand toys are great for this because they require less effort from you but still get him moving. I am personally not a fan of frequent laser usage because they can never really catch it which can lead to frustration. Also get a ball track toy (mine love ones with rattle/bells in the balls) or butterfly toy that he can go after while you are away. 

We have 2 cat trees for them . We play with em every once and awhile . They usually play with each other and run around the house like crazy but I'll make it a routine that I play with them every morning and night. But Rudy is calm right now and doesn't seem to be aggressive I hope I wake up tomorrow and he is calm. Here is a pic of him and Jay right now

Great, thank you for all the information. This is very helpful.

Kieka gives GREAT advice. I think she is exactly right and her advice is spot on.

I am so glad to hear that the cats seem confident. Walking around with their tails up, not hiding, etc. You are doing a great job with them.

I asked about outside cats because often times having cats come around (especially cats that aren't spayed and neutered) can cause territorial insecurity among the resident cats. So imagine if you were living in your house and strange people were walking around the windows outside and looking in the windows etc. You would feel uncomfortable. Same with cats. Then with cats they can feel insecure and then redirect their frustration and anger to other cats in the house or even humans. Cats want to "own" their territory so they can feel safe and secure. When something disrupts that (ferals, strangers, etc) they can get stressed and act out.

I would add one thing, after a good play session feed either treats or a meal. That gives them the confidence like they have hunting outside. Hunt, capture, kill, eat.

I am glad to hear that since Rudy stopped going outside he was doing better. So maybe the outside ferals are not a big issue going forward. Let's monitor that though going forward.

So the latest outburst was triggered by that lady. It made him feel insecure and stressed. He sadly took it out on Jay. Jay is not the problem. I think you are doing a great job playing with them and that will help Rudy feel like he owns the territory again. Once he feels more secure and confident he should stop attacking Jay. 

Thank you for sharing the pics, they are absolutely adorable!! We want Rudy to feel safe and secure again in his territory and I know you can achieve that. We then should see no more attacks. Hopefully the attacks will stop very soon. I know they are in good hands with you, you can do it.

Please ask anything anytime, I am sure Kieka and I are both very happy to help you anytime for as long as you need us.