Shyla will be 15 soon and is the last of four cats. We rescued her and a sister at the approximate age of 6 months from the streets. She has enjoyed her role as Only Cat, since the other three didn’t really include her in their playing. On New Year’s Eve day, an acquaintance begged me to take a 4 month old kitten he found. I brought Summer home and gradually introduced Shyla to her. Shortly after that, Shyla was diagnosed with either inflammatory bowel disease or carcinoma of the intestine. She is receiving palliative treatment at home. Because Summer wants to play and Shyla never learned, and is now too sick to be bothered, we adopted 7 month old Prissy from a rescue organization at the end of February. We took a lot of time introducing Summer and Shyla to Prissy. The two kittens have become great friends, but Prissy growls and hisses often when she sees Shyla. More recently she has become aggressive toward her. She ran over to where Shyla was sleeping, started growling, and then thumped her with her paw. Poor Shyla isn’t strong enough to fight back and only hisses at her and takes a defensive posture. Prissy has done this several times within the past few days and even though we try to direct her attention to a toy or one of us, we are afraid to leave Shyla out of our sight. Shyla won’t be with us too much longer. She’s not happy having these intruders, so we want to make sure she can spend the rest of her days in peace. How can we change Prissy’s behavior toward her? Separating them both isn’t fair to either of them, but we don’t know any other method to stop this aggression.