FIP -- Need Some Opinions Please

I purchased a Persian about six months ago now. When I first got her she had horrible diarrhea which we figured was from the stress of flying and coming into a new environment. She was on antibiotics on and off for a couple of months, we did the food change, and de-wormings and eventually the diarrhea stopped. That was about 3 months ago now. She has not grown much since we got her. She was only 4lbs 3oz a month ago (at 9 months old) and I was concerned and brought her to the vets. She had a slight belly on her at that time and so the vet thought that maybe she had FIP. She said her organs felt normal sized and the test came back saying the protein level was normal. So the vet figured she was just a small cat. In the last month she has gained a pound and her stomach has become very bloated. Today I took her to the vets and they did an ultrasound and then an xray which showed that her stomach was FULL of fluid. The vet took a sample of it (which was clear) and another sample of blood and is sending them away. She is almost 100% sure she has FIP at this point. Needless to say, I am heart broken.

I am not only concerned about my Persian but also my other two cats who have been around her the last six months... one of which is my five year old sons pride and joy. He would be devestated if any thing were to happen to him.

I guess my question is... how likely is it that my other two cats will also get sick?

Thank you for your time.

I had a FIP positive cat that lived with 5 other cats for 18 months. No one else in the house contracted it from him. Cats with FIP are exposed to the corona virus, and the vets that I've talked to on the topic seem to think that a cat must have a genetic predisposition for it for the virus to turn into FIP. Since a very high percentage of cats test positive for the corona virus, and only a small percent every contract FIP, the odds are with you that your others will not get it.

FIP is the most misdiagnosed illness that I've come across. The only way to diagnose it for certain is run tests after they cross.

Sending that she doesn't have FIP.

With FIP, the fluid tends to be yellow rather than clear. Hopefully the blood test and fluid test will give you more insight as to what may be going on. You might want to look over this article, which lists *some* other possibilities--it's not an exhaustive list by any stretch of the imagination.
http://www.petplace.com/cats/ascites-in-cats/page1.aspx

My cat Willow died of FIP (confirmed via necropsy) at the age of 9. The other cat who she lived with, Odo, was about 14 years old at the time. It's been a year and a half since she passed, and he has not had any major medial issues or signs of FIP. I adopted another cat, Zek, not long after Willow passed. He too has shown no signs of contracting the illness. The best thing you can do while you wait is to try to keep things as low stress as possible--stick to their normal routines as much as you can.

Good luck. I look forward to seeing the test results, and I hope that it is something treatable.