Need advice on handling territorial aggression

Hi, I've posted on this forum before. This summer I trapped, fixed, and adopted two feral kittens. I took Harry into my home when he was between 3-4 months old, and then 5 weeks later, I took in Mia, who was 10 months old. Harry has been with me for 15 weeks, and Mia for 10.

Mia had a bad reaction to the anesthesia during the spay and suffered liver damage (which was temporary, thankfully), got an infection, wouldn’t eat for several days, and I nearly lost her. I syringe fed her, did a round of antibiotics, and during the course of her veterinary care, learned that she had been shot and has a bullet lodged in her pelvic area. It had broken her leg, which healed, but the leg healed funny. There’s nothing they can do about the bullet, but it poses no danger. Mia has made a full recovery and can run well and jump about two feet, but she walks with a gait, and she’s mentally a bit slow. At first Harry and Mia seemed to like each other, and although Harry played kind of rough with her, I thought they acted like brother and sister (and there’s a good chance they are brother and sister). However, for the past 3 weeks, Harry will not allow Mia to go downstairs, and will only let her go into 2 of the 3 upstairs rooms. He gets very aggressive towards her and has scratched her on the face a few times. She is scared of him. I would really like Mia to be able to go downstairs, but even when I put Harry in a room by herself, she’s scared to be downstairs.

I have two other elderly cats. One bullied her but no longer does so, the other one sleeps all the time. They ALL get LOTS of love and attention from me.

Feliway has NOT been effective.

Anyone have any behavioral strategies for how I can deal with this? Will Harry eventually mellow out and allow her to go downstairs?  

It could be a couple of things:

Had she been to the vet when the behavior started?  He may be smelling something on her he doesn't like.  You can use vanilla extract and stroke their coats lightly with it.  It will make them smell the same.  Brushing them both with the same brush does something similar.

He may also be growing and his hormones are making him nuts. (he's fixed, right?)

It occurred to me that there's a chance that there may also be another cat outside that he's reacting to.

There are calming treats that might help.  I found mine on Amazon.

At this point, you can nip the behavior in the bud - which means being close by and stopping it (a sharp hiss, a can of coins rattled, clapping and a firm "no.") when it is happening.

Good luck.  Mia has come through a lot.  Thanks for helping them both!

She has not been to the vet in 14 weeks. I don’t think that’s it.

There are currently no feral cats on my block other than Harry’s papa cat. Harry was neutered over two months ago. Also, he co-exists well with my other two cats.

He is really jealous of her, I think that’s the core issue. I give him lots of attention. I also yell “No” when he’s bullying her, and give him time outs in a separate room. He knows I don’t like him bothering her, but does it anyway.

When I first brought Harry in and he didn’t get along with the two elder cats, I put him in a pet carrier downstairs so he could get used to the other cats and they to him. That worked pretty well. I wonder if I should put him in the carrier downstairs for a half hour a day and try to get her to come downstairs so he can get used to her being downstairs, or put her in the pet carrier while he’s downstairs. I think what I need is sound behavioral strategy advice—not advice about treats or chemical solutions.

Thanks!

I should also explain thay she has a room that she considers hers upstairs with a litter boc and food and water. Only Harry uses her litter box sometimes and eats her food, the others drink her water but use their own foid and litter boxes downstairs. I guess I could move her stuff downstairs so she'd have to go downstairs but I don't want to stress her.

No, dont move her gears downstair.   she shall feel safe at least in her own room.  the only problem is harry has access to this room and uses the toilette. Which in part is a dominancy thing.  It perhaps cant be helped.  Absolute equility is almost impossible with the bully.

But if it becomes a problem, you could have a cat door with magnetic lock on it, with only Mia having this magnetic unlocking collar on her.

I suppose you could try this with  one of them in the carrier, or a big dog cage, like you suggested.  Shouldnt hurt, may help.

Good luck!

I tried the cage option and it did help a bit.  I used a large dog cage and covered in with a sheet on 3 sides.  My resident cat, Jake was the only willing participant to go inside the cage and in order for him to feel safe, I covered it for him.  I would sit with the cat and feed them both yummy yummy treats.  I used cooked plain chicken.  I would move the chicken closer and closer together so that they were almost touching each other while eating.  I also played string with them.  I chose to keep the interaction short.  I did it 2-3x a day but only for a max of 20 minutes.  If I tried to go longer, Jake who was inside the cage got very agitated.  I also would play with them and feed the chicken on either side of a gate.  I needed help for this one as I didn't want either cat to try and jump the gate.  I also used a water bottle.  I would squirt the aggressor in the butt and then scoot them off for a time out.  This was very effective. 

I have also used Composure treats and Composure Max liquid for calming.  I prefer the liquid as it works faster, but it's much more expensive.  The treats work well, but at first the cat needs at least 3 treats so the 30 in a package goes quickly. 

Safe Space for Cats by Spirit Essence works well too.  I am using it on Jake as he was the one who was afraid of Marvin.  He is much more at ease now.

The screen door that I have used is also a great resource.  The cat can be safely in the room, but still see, hear and smell what is going on around the house.  The cats can also get right up to each other without hurting each other.  I have posted pictures of my set up frequently and if you'd like I will post a picture.  I bought a cheap ($20) screen door from Lowes and attached it with cheap ($4) tension rods.  The door didn't have to be taken down or defaced in any way. 

I know how stressful it can be having cats that do not get along.  I have been working with Marvin and Jake since mid August.  We have lots of improvement, but I absolutely cannot leave them unattended.  When I am not home, one is put away.  At night, Marvin continues to be in his safe room (which he loves) with the door closed.  As of now they pretty much ignore each other.  They stay on opposite sides of the house.  When they see each other, one may hiss, but that's it.  I don't think they will ever be buddies, but that is ok.  I just need them to coexist.