Sudden Agression !

We Have 2 Cats That Are Brother And Sister. They Got On Well With Each Other Until Yesterday! They Are Both House Cats. Olly(the Tom Cat) Escaped To The Outdoors And Was Outside For 4 Hours Or So, We Did Not Know He Was Out Until He Was Seen At The Rear Door. When He Was Let Back In Libby (his Sister) Was Very Aggresive Towards Him , Hissing And Spitting And Now Wants To Fight With Him ,it Would Seem As If She Does Not Recognitsize Him
Or Some Smell Is Making Her Like This? Help

She probably doesn't recognize him--he smells different after having been outdoors.

Try putting a bit of vanilla at the base of both their tails--that way they will smell the same to each other.

They should recognize each other sooner or later. After a while indoors, their smells will be the same again.

Hi there greengrass!

I had EXACTLY the same problem last week with my 2 indoor orientals. They both got outside for 1/2 hour or so, when I got them back inside they were aggressive towards each other. I did the vanilla thing (under chins, between shoulder and at base of tail) which I think helped.

They were a bit better the next day and completely back to normal with each other in 2 days.

Fingers crossed that you find the same thing happens with yours!