I'm sorry to hear this. Is there any way you can keep them separated until he can be started on the prozac? When I tried it on Storm, I was told that it might take a while but it seemed to help calm him pretty quickly. Over time though, it just made him sleep all of the time and then he also became anorexic so I had to stop giving it to him. The vet said that sometimes this will be side effect but usually only dogs sometimes become anorexic. Good luck.