It took the older one a little while. They get along now but my older kitty is really sick and the vet can't figure out what is wrong. That's the reason I joined this forum is to hear if anyone has heard of this happening (his symptoms etc). However, this site is kind of confusing to me, and it won't let me post under the health forum, although I've already tried to make those first 3 posts to become activated.
Both domestic short hairs. We rescued Spartacus from the pound (white, with gray ears, tail, he looks like he has a little Siamese in him) and Luna was found at a business when she was around 4 or 5 weeks old. She's all black.