I recently adopted a 3 year old female, just about a month ago. At first she and my 15 y.o. were doing okay, just a little hissing but no fights. Now though, she WILL NOT stop chasing him. It might not be a problem, except that the 15 year old has arthritis and all the chasing makes it so he can barely walk some days. He's then turned to biting me instead of channeling his anger into her, which isn't good either. New cat has also started peeing on my bed.
I introduced them slowly at first, and I've tried separating and re-introducing slowly, but nothing seems to help, as soon as I'm not in the room staring at them she chases him around until he gets sore, and then he comes over and bites me, and I mean REALLY attacks me. I've also tried vetriscience and petco calming treats, and Feliway spray, but none of that helps either.
What else can I do to help calm them down, and to help my 15 y.o. not be in so much pain?