Strange symptoms, FIP hasn't been ruled out

Good evening, I joined the site today just to run my situation by you folks and to get some info and ideas on how to help my little guy. My cat Vader is a 9 month old rescue, he had a URI when I first got him and was treated with atibiotics (@ 4-5 mo old) he developed uveitis in his right eye (started Dec 7) which was treated with various drops (anti-inflammatory & antibiotic) and we treated for toxaplasmosis w/ clindamycin. The uveitis didn't really respond to that treatment so we discontinued. We found he had roundworms and we treated him for that - his uveitis appeared to get better after the dewormer, then it went back, then after the 2nd round of dewormer it got better again (never all the way gone, but better) about 2-ish weeks ago it moved into the other eye and I decided to take him to an opthamologist, where they suggested we test for corona virus. Amidst all of this he developed another URI and we put him back on azithromycin for that (10 day course, which he has finished). We drew blood for the Corona virus test, which stupid me not knowing any better asked them to JUST do that test instead of all of the companion testing that often goes with it so essentially I put my poor guy through the stress of a blood draw for basically nothing. The test results came back positive for corona virus 1:12800 which I understand is very high, however I also know that it isn't a reliable indicator for FIP. Vader is eating well and peeing and pooping normally. He always had loose mucousy stinky stool until we put him on the Science Diet I/D - and it's been like a miracle cure, his poops are totally normal with no odor whatsoever. I understand the corona virus can cause stomach issues so that part makes sense. I give him Viralys daily (recently I upped it to twice daily) and I made a big batch of chicken bone broth to help his tummy. He gets 1/2 a 5.5 oz can of wet food and 1/4 cup shredded boiled chicken with 4 heaping scoops of the broth (I warm it up because Lord Vader prefers it that way) I just started adding a pinch of probiotics to his meals too. He isn't filling with fluid, he's growing and gaining weight normally... We have upcoming appointments with an internist as well as a holistic/alternative vet. He has a paunchy flabby belly that I never really noticed before that has me a little freaked out, but it's flabby, not hard and it's in the "primordial pouch" area so I'm hoping it's just a normal part of his anatomy. His coat looks beautiful (it actually looks nicer now than it ever has).
So after this novella comes my question(s) - has anyone had a cat with a suspected case of FIP with similar titre levels that DIDNT ultimately have FIP. And what was the ultimate diagnosis once FIP was ruled out? Thank you so much for your help, time, info and support. I've read many of the other postings

I had never even heard of FIP until my healthy as a bull 10 month old boy passed away from it just this October. It happened VERY quickly; from the first sign of sniffles to being gone in about two days. From what I understand of what I've read since, wet FIP- the kind that causes the fluid accumulation in the abdomen- kills very very quickly. It took down my boy in about two days and he had never so much as had a sniffle in his life before that. If your kitty is already sick I would only think the FIP would take him down even faster. Not saying it isn't FIP (there is a dry form as well) but something to keep in mind.

Someone else more familiar with the disease may be of more help. 

Thank you for your response, and I'm so sorry you lost your boy to that nasty disease. It would appear as though Vader is feeling much better, he's impatient for breakfast and following me around the house again. He is still stuffy and his pupils are a bit off (the right always seems to be smaller than the left) and he still has the uveitis but it seems like he's feeling better. I'm so hopeful that his improvement is a sign that it isn't FIP. I haven't found much info on whether or not it's possible for a cat with FIP to improve without treatment but then get sick again. It so frustrating to not have a concrete diagnosis and a clear treatment plan.

Thank you.

Unfortunately with FIP a concrete diagnoses is usually not possible until after the kitty has passed and they can do a necropsy. I insisted on one with my boy which is the only reason I know for sure it was the FIP. I hope your boy continues to get better. FIP isn't something I'd wish on my worst enemy

You can take some solace in the fact that a very high percentage of cats have been exposed to the corona virus and never go on to develop FIP.

Most just get the URI symptoms, then their immune system kicks in and most often, along with some Veterinary intervention, they get better.  In a small number of cats, the corona virus mutates into the deadly form, resulting in FIP. 

Unfortunately as of yet there is no cure once the virus mutates. From your description it sounds like your boy Vader is on the mend. 

Being positive for corona virus does not mean he has FIP.  It only means he has or had the corona virus.  If that test was negative, it would rule OUT FIP, but being positive does not rule it in.  It just makes it possible, now or in the future, since FIP is the result of the corona virus MUTATING.  In the absence of symptoms, the best thing you can do is keep him happy and stress free as much as possible.  There is no concrete diagnosis for FIP in the absence of sickness.  Even those with DRY FIP can get sick and then get better and then get sick again, many times over, before the FIP eventually wins.  There is no treatment, so if you diagnosed it now, I would say the same thing, keep him stress free and comfortable as long as you can. If you can get him to two years of age and still healthy, chances are you are home free.  Most cases of FIP occur in cats under two years of age.  Not ALL cases, mind you, but MOST.  I have had way too much experience with this disease and have studied it extensively.  I have only lost one that was over 2 years of age, and he had been seriously stressed (dumped in a park, abandoned by his former owners).  He got the dry form and went on for a long time getting better and then worse, but finally he refused to eat, dropped an enormous amount of weight, and then it became the wet form so we put him to sleep so he wouldn't suffer.  But he knew love and comfort for months before then.  I wish I could have done something to save him but there's nothing to be done that won't just prolong suffering.

Yes, the FIP virus can cause uveitis, but so can other viruses, bacterial infections, parasites and fungi.  You said it got better after worming, twice, so you may want to worm him every 3 weeks for awhile just in case worms are the cause.  Worming is not stressful and the three-week interval makes sure that new worms will be killed before they are mature enough to make more eggs that will turn into new adults. 

In my experience with FIP, the first thing that goes is appetite, and the weight loss is even faster than the lack of appetite would cause.  Another indication is a low-grade fever that doesn't respond to antibiotics.  It doesn't sound like your guy has either of these signs.  If he were mine, I would keep doing what you are doing but not overload him with trips to multiple vets (stressful) unless the uveitis is causing him pain, in which case get meds for it.  Don't go away on a trip and board him (stressful) nor add any new cats or dogs to the household (generally stressful), and do drink stress relieving herbal tea yourself and try not to worry.  Calm is the key here, both yours and his.  You can do no harm by doing everything you are doing at home, good food, good love, good grooming -- and take care of yourself, because they sense our stress and react to it.  Remember, there is really no treatment for FIP, other than treating the symptoms and keeping them comfortable as long as you can, so there's no reason to rush to diagnosis.

The first indications we had that Darcy was sick was when she went from her usual active, playful self to hiding under the bed. I thought it was a cold and that a trip to the vet and some meds, and she would be good as new. However, when the Tech took her temperature she left the room and came back with a second thermometer to try - because it was so high. We put her through a lot of tests, gave her a lot of medicines, until we accepted that it was FIP and then just gave her as good a life as we could until it got to be too much for her.  I don't have a lot of experience with FIP, but I've come to associate the high fever with the disease. When we took our new cat in for cold symptoms and the vet said "she feels warm," I (internally) freaked out.  She was okay, though, no fever. 

I hope and pray your kitty does not have FIP, it's a horrible, terrible disease that no kitten should have to suffer from. I will forever miss my beautiful, sweet, loving little Darcy.