The only thing I know of that is routinely screened for is FeLV/FIV, the others are only tested for (in my experience) when the cat shows signs of illness (unless you're a paranoid person like me and routinely test every new kitty that comes into the home). As for the giardia, as Brigitte pointed out, it is in most water sources so very difficult to get away from. It's not that it goes dormant, it's just not normally present at a level to where it will cause illness. However, stress can change that and allow it to flare. I believe a PCR is usually sensitive enough to pick up giardia even when it's not at high levels, but it is also true that even the most sensitive test is not 100% accurate, so you can get false negatives, and false positives as well.
I bet I'm dealing with both. Giardia flare up and a tape worm which we haven't seen worms since round 1 of panacur so after this I'm betting we're good. His eye is seemingly better at times but we still have more days to go @ 4x per day. He's certainly been stressed, new home, new food, new litter, new friend...I'm considering putting him back in quarantine because he's taking on some on Jengo's skittishness and why wouldn't he? These meds are scary and invasive, particularly the eye drops. It's been a bit of a role reversal the last week, Jengo is more social but Biz is less.
It's frustrating to get false negatives. It's all frustrating. I just want to do what's best for my babies and not getting clear answers is upsetting. Having him on medication always is sad for us. Outside of that, he's been an amazing blessing and a good friend to Jengo, we adore him. We will keep medicating everyone and testing every one until he's better.
We screen everyone too, we got Biz on a Saturday and dropped a fecal sample Sunday and had him seen by the vet Monday.
This, no matter how frustrating is good, I would love to get involved at some point with rescuing/fostering and so it's all good experiences to have. It's easy to get mad at the vet especially when they've made snide comments about Savannah's.
The good news also is that Jengo has remained pretty healthy in spite of it all. He could never endure what a Biz has. Biz is a fighter and tough little guy. He's strong and willing.
Does anyone have suggestions for probiotics? It's a good idea for both kitties and Jengo gets stopped up easily and the other has too much. I bet they could both benefit.