Oh, I'm so sorry! FIP is such a horrible horrible disease! I lost one of my babies to it several months ago. Sadly, it is one of those diseases for which there is no cure. From what I know of this disease, once they start showing symptoms, the kitty generally has anywhere from a few weeks to a few months left. FIP is also a difficult disease to diagnose, but the fluid in the abdomen is usually a dead give-away. I think there are treatments to slow the disease, but nothing to stop it. You'll want to keep Wallace isolated from Winston, and be sure to get Winston tested to. But even if Wallace does have FIP and Winston comes up positive also, it's not a sure thing that Winston will get FIP. It just means that he's been exposed. The disease could manifest in a few months, a few years, or never.

I'll be saying a prayer for you all! PM me if you need someone to talk to!