Oh, yeah, definitely. Vets don't always get it right. Our guy definitely has asthma as far as I can tell. He was incredibly sick twice with the virus right after we got him. He's fine now, but we do we give him a chewable lysine supplement, I second that for sure!
I second the rescenting suggestion. One of my guys does this everytime any of the other cats leave. I am pretty sure he is freaked out by the "new" smells on the other cat when they return from the vet. It's gotten better over time though.
We tried that too (I appreciate you taking the time to leave the advice!). He's just unfortunate lol. We got him from a shelter with as a kitten with an untreated, nasty upper respiratory infection that took months to clear, so I wasn't shocked when he ended up with asthma. The shelter just...