First, some background. I know this is gonna be looong, but I want to give the whole story: My F2 Savannah (who will turn 1 on Nov. 13 if he lives that long) behaves more like an F1 or a Serval sometimes. He is very standoffish to strangers or really anyone besides me. If someone tries to corner him to pet him, they will be partially shredded by the time they can change their minds. With me, he is "normal," playful, affectionate, and mischevious. I often forget how "wild" he is until I see him w/someone else.

Having been in the hospital the better part of 2 months, I had my dad staying at my house w/the animals. He rarely was able to interact w/Tsavo at all. I came home w/the baby (finally!) about 2 weeks ago, but still had Dad here often and have had many visitors, so I have hardly seen much of Tsavo myself. If he so much as hears unfamiliar voices, he won't show himself. I knew all the stress of me being gone had gotten to him, so I didn't push him.

4 days ago was the first time no one had stopped by all day, so after dinner he decided the coast was clear and he could come say hi. I was shocked and sickened at his appearance.

He is absolutely emaciated (he was very lean and muscular), his usually GORGEOUS coat is greasy, clumpy, and ratty, with tons of it falling out, he's lethargic, breathing is labored, and his meow sounds weird. His purring sounds odd too, like there's fluid in his lungs possibly. Naturally, I'm freaking out b/c I had played w/him one day about 2 weeks prior to that when no one was around and I stopped by, and I was thinking how beautifully he was maturing and what great shape he was in. My first thought was FIP, although his abdomen is not obviously distended like I have seen w/effusive FIP in the past. Also, he is not wheezing...just breathing a bit more laboriously than normal. No discharge in eyes, pupils are symmetrical, no vomiting, no diarrhea....really nothing other than looking like absolute $h!+.

I took him to the vet, assuming the absolute worst, guessing that he's one of the lucky ones where Corona mutates and I'd certainly given him enough stress to cause it to happen now. The vet asked about FeLV. I said I was almost positive he couldn't have it b/c my other cats have been tested (both rescues) and he came from a very very conscientious breeder and he has never been outside. Plus, the speed in which he went downhill was shocking, consistent w/FIP. He had been healthy as a horse until now w/the exception of a kitten cold at one point, which made me wonder looking back if that was the precursor. He wanted to do a snap test just to rule it out and it came back positive. I was stunned.

Naturally, being the research junkie I am, I have read everything I can get my hands on about this and the accuracy of the test. Sounds to me like false positives are not unusual at all, particularly when there is some other major thing going on w/the cat. Many times and ELISA will come back positive, only to have the IFA or a bone marrow test be negative. I asked his breeder, and he said he had heard of false positives in F1s but not F2s (yet). He's a genetics professor and he believes there is something in the hybrids' blood that throws that ELISA off on that particular test. He has gone so far as testing bone marrow on several of his breeders to ensure negative FeLV status. Tsavo's mother is 12 years old and has been tested, but only blood tests. With the nature of FeLV, one would think a 12yr old cat would probably have caught SOMETHING by now to trigger a secondary illness, unless she is one of those cats who hides it in their bone marrow, keeps it in check so that her blood tests are negative, but at some point when he was nursing or in utero, was shedding the virus but remaining unaffected herself.

The ELISA itself seems to frequently register false positives, even in plain old domestic cats. Here's where my confusion sets in; I don't know what I should do about further testing and my other cats. I'm hoping someone here has experience w/this. My 2other cats are 6-7 and 12-13, respectively- not a high-risk group for catching FeLV or FIP, but I'm somewhat concerned that possibly one of THEM has FeLV (though they both tested negative when acquired) and gave it to Tsavo when he was a tiny kitten.

Should I get both my others snap tested and go from there? Or wait til I get Tsavo's PCR results on the FIP? Or retest him for FeLV via blood test? Right now I am giving him Clavamox in case it's a secondary FeLV illness and not FIP. FIP PCR should be in today or tomorrow. Has anyone had a similar situation or experience w/false positives/negatives??? Especially in hybrids? It was bad enough when I realized I was losing Tsavo...but if it's FeLV, then I could lose all 3.

I should mention that he did not have a fever- his temp was low at 99.2, his white blood cell count was elevated (though I don't remember how high) and his liver enzymes were up.

Someone on this board HAS to have experience w/this....

I don't know a whole lot about hybrids...
but when I was volunteering and later working at a shelter we had a fair share of false positives. We would usually isolate, and re-test at a later date. The isolation was a separate air source, but all the animals in there were sick.
I wonder often about false negatives with tests done as well. I can't remember false negatives, really. Just the positives.
I know that there were sometimes so many animals tested in one day that mix ups DID happen. Not alot, but some.
I know that FIP can be dormant until much later, when it shows up full force, but I don't know if it would test positive or not during that time.
I am had heard that some illnesses can be present, but show up as a negative until there is enough there to register.
In any case, I don't think that testing the other 2 would ever be a bad thing to do.
If you haven't already, isolate to the best of your ability...
here are some things I came across in research
http://cats.lovetoknow.com/Cat_Eye_Problems
http://www.animalhealthchannel.com/fip/symptoms.shtml
best of luck! So sorry to hear about this.

edit...
I almost forgot - did your vet tell you that FIP is contagious as well?

Edited by Cameron Feathers (10/08/2009 12:26 PM)
Edit reason: add question

One other thing, if he has "dry" FIP, he may NOT get a distended abdomen. The distention is a result of the fluid, I think...Any plans on re-test for FeLV?

Thanks for the reply, Cameron. I am pretty familiar w/FIP, but the FeLV diagnosis really threw me. THAT'S the one I doubt the reliability of the test for. I know that false positives are prevalent w/the ELISA. If he has FIP, it's not effusive, unless it's in his lungs (possible) that the fluid is collecting, b/c he doesn't have the typical distended abdomen. The reason I have any doubt about FIP at all is that he also doesn't have any of the neurological symptoms of dry FIP either, plus no fever, plus the fact that the cats I've seen w/it get worse very quickly. Though he looks awful, he's no worse than he was 4 days ago. Sometimes I think he seems a little better, but that could be wishful thinking.

Were you talking about false positives on the ELISA for FIP or FeLV? It's my understanding that there is no truly accurate diagnosis for FIP except post mortem tissue examination.

They are separated now, though I wonder what the point of separating him now is...they've all been together his whole life except for the past 4 days. Now I get to listen to them crying for each other through my vents from the downstairs to upstairs.

FIP can be contagious, but more so as the corona virus, as I have understood it. A cat must have that, plus the genetic predisposition for the virus to mutate from relatively common corona to deadly FIP. I guess I hope for my others' sake that it's FIP and not FeLV, although for Tsavo's sake, if it's FeLV, that's treatable and he could potentially have years left if he can beat whatever is keeping him down right now.

I know I'm rambling but I am just really upset and trying to wrap my head around the best course of action and hoping someone can tell me w/greater certainty how accurate/inaccurate these ELISAs are, and also if someone had a similar situation w/personal cats, not in a shelter, that would be very helpful. Looking for any source of hope!

the false positives were for ELISA as well as FeLV

There was one cat who was a false positive on FeLV at the shelter... he was relocated to the FeLV room, and lived there for nearly 6 months before it was realized that he either did not have it, or developed an immunity to it (he tested negative 2 times after 6 months living with the FeLV cats)

In any case, I will keep you guys in my thoughts.

Thanks. They've recently discovered now that a cat can be FeLV positive, then it's immune system can keep the virus in check, and store it in the bone marrow where it's undetectable...yet still carry it and possibly infect others. Fantastic.

Can't my cat get something they can positively diagnose???
This absolutely sucks. How can I decide what to do when I don't even know for sure what he really has?

Ugh, this all makes me nervous about my cats storing FeLV....I don't have anything useful to add, other than that I'm sorry and thinking of you guys.

I have nothing to add either, but you and your kitties are definitely in my thoughts. I found a lump on my 8 year old cat about a month ago, and it was just an abscess, but I did blood work anyway. Would the labs have tested for FeLV? She seems healthy now, but this sounds scary.

Anyway, I hope for the quickest recovery and wish I could offer more help