It is so difficult to know which kitty is the source and I guess it doesn't really matter if you intend to keep them all together. It can be risky introducing new cats to existing ones and one only hopes that there is not a carrier of something. But, hey, things happen, and often there is something new brought into the house. Breeders and shelters always have problems with things like this. Maybe you could contact a shelter to see how they deal with it and if they ever found a way to clear it up with existing cats other than adopting them out...... just a thought.

I would like to believe that once they all have mature immune systems, the carrier will be able to keep it under control and not create break outs again.

This can be sooooo frustrating, for sure! I don't envy you at all.

Sas and her campers