Advice needed about my brother and sister cats

[mollymoses1950]

My cat went missing for 24 hours and on his return his sister just is hissing at him all the time and they used to be very close , i just hoped someone might have an idea what this could be ?

This happened when one of my cats went missing (for 5 days). They took a while to get on again, as if they didn't remember each other. But they were a bit grumpy with each other anyway. They were back to normal in a couple of weeks.

Maybe he's just furious with her for disappearing and is reminding her that he's cross

5 days thats a long time , yeah lets hope she comes around as they were very close

Does he smell different, perhaps? How does his coat look?

i cant smell anything but when he came back he was wet and his coat was a bit rough looking, it was windy and raining when he went missing

You haven't got her sensitive nose though - maybe he spent the night somewhere with an odour that she doesn't like. (Or that's a bit different anyway.) I'd stick strictly to routines tonight and see how they are in the morning.

Are they getting on better again now? X

It could well be he smells different, maybe of an un-neutered female cat, which to another female would seem a huge threat.

Even when cats are neutered, their "urges" don't always disappear, so he could have been making overtures to an intact female.