Not getting along anymore

I adopted to Oriental Shorthair siblings, Sasha and Brady, 2 months ago. At that time, they were 4 months old and got along really well. They were of about equal size and loved to chase each other, sleep together, etc. In the last few weeks, their relationship has changed. Brady started to really grow and become more aggressive. Now, he often bites her neck, chews on her tail, chews on her ears, bites her side, etc. Sasha is then often forced to assume a defensive posture, laying on her back and kicking him with her back feet. She does not hiss but lets out meows that definitely siganl annoyance, and perhaps some pain.

I am saddened by this because they used to be so close and I am almost regretting adopting 2 kittens, instead of one. I just want them both to be happy, but Sasha doesn't seem happy any more. I should mention that Brady was neutered a month ago and Sasha will be spayed in a week. They were at the vet recently and their health appears to be fine.

What might be causing Brady's behaviour? Could it be some sort of male/sexual aggression, even though he is neutered? Is it territorial/dominance, or is he just aggressive when he plays? Should I separate them when Brady goes after Sasha? Would Feliway help and is there anything else I can do? This is really upsetting me.

Thank you so much for your help,

Carlie

Well if they are 6 months old then that means that Brady wasn't neutered until they were 5 months old and allowed contact with her for the past month right? She could be pregnant by him. at 4-5 months cats become sexually mature. Males have active sperm for a month after being neutered and it takes that long for the hormones to leave their systems. If they have had contact for the past month, he was sexually mature and so was she so she could very well be prego. They are young so she may not but you never know. Just be aware that it is very possible.

That could obviously be one thing causing the difference in acting.

But nothing really sounds wring with what you said. it sounds like they are playing. but the neck biting, that is mating behavior and if they have been doing that for the past month...I don't know...

Welcome to TCS and congratulations on adopting 2 kitties Ahh, sibling rivalry It could be as Jen said, that the male is still feeling those hormones, even if just to be aggressive, not necessarily trying to mate Here is an article from Cats International that might be of interest to you:http://www.catsinternational.org/art...g_a_house.html
Please keep us posted and by the way, we LOVE pics here at TCS

Thank you for the warm welcome. Brady was neutered at 4.5 months of age before he showed any signs of sexual maturity (spraying, mounting and biting her neck, etc.). Also, Sasha has not gone into heat (at least not in an obvious way). She has not been extra affectionate, more vocal, pushed her bum in the air, or any of the other things that I expect from a cat in heat. However, I'm far from an expert so thanks for bringing up the possibility that she may be pregnant. I get the feeling that it's a combination of play aggression and dominance. She'll be spayed on Nov. 3, so I'll be finding out.

I will definitely be doing early neutering/spaying in the future to prevent unnecessary worry. I'll keep you all posted and post some pictures soon.

Carlie