Background: We have two 2 year old cats that are brother and sister. They came from a litter of six and we've had them since they were 12 weeks old. They're indoor cats and have no outdoor access due to us living in a flat.
On Wednesday, we had to take the girl cat to the vets. Turns out she had a septic uterus, and they kept her in overnight for an emergency operation to remove it the next day. Operation went well and she came home Thursday night. However, she's had a cone on her to stop her licking her wound and as a result she's pretty miserable - she's eating/drinking fine but has spent most of the time sat with one of us on the sofa dozing.
Her brother, however, is NOT happy. He wants to play/see her and doesn't understand why he can't. She's feeling vulnerable and has started hissing at him and getting defensive when he comes close, but this just results in him looking lost and miserable and last night he was really upset that they had to be separated overnight to keep her calm.
Any advice what we can do?? I'm shattered from him being up most of the night crying for his sister, but we can't leave them together because she's so scared at the moment. They never fought or had issues before this.
TIA 