I need advice, I have no idea what to do with my two cats. They are 18 month old brothers and were raised as indoor cats, which was fine until we started harness walking them more and more. One of them got a taste for the outdoors and started wailing constantly to go outside. When we moved house at the end of May, we couldn’t take it any more and it was clearly stressing him out. No matter how much stimulation, cuddles, play, puzzle feeders etc we gave him he would still scream constantly to go outside. We got a tracking collar and started letting him out. Our new neighbourhood has a lot of cats, and this has caused some even worse behavioural issues in him. Other cats wind him up outside, then he will come in and hiss/growl/swipe at his brother every time they’re close. We’ve had to completely separate them. We tried keeping him inside to try and reintroduce them, but he just screamed and screamed again to get out, and eventually we had to take him to the vet because he had stopped eating and was having diarrhoea from the stress. She said we needed to let him out.

We’ve tried everything - more enrichment, more hiding places, pheromones, time outside, separating them completely and only having them together at positive times (treats etc), more litter trays, so much stuff but nothing is working. He still hates his brother and is even now yowling and growling at us if he’s wound up and we approach him.

He’s had full bloods and an ultrasound and all they could find was mild IBS so it’s not a medical issue. I just don’t know what to do at all and it’s making my life an anxious mess. They used to love each other. He still has happy cuddle times, but it’s getting less and less. Please help.

Desperate please help