Help!

[tmwick10]

My cats who used to get along suddenly are at each other. My older male Bradley was ill yesterday. His sister was sitting near him while he was vomiting. She suddenly thought Bradley was playing with her and she chased him around the home. Since yesterday they have been at each other growling and hissing. Anyone have ideas on what caused this and what to do?

 

[wakawaka36]

First, a question. Which cat is more aggressive, Bradley or his sister? Sometimes when cats get sick they are more territorial as to avoid being bothered. If Bradley is the aggressor you could keep him in a room for a day until it's all gone, and then re introduce them. 

 

[tmwick10]

It is his sister Lola who started it all. We have done the seperation thing today which seems to be working for the most part. They are still yowling and hissing when they get too close.