Nobody seems to know what's wrong with her 
. I've got a quote here for the best part of £700 to redo all the tests she had in March, so abdominal scan, chest x ray and FIP testing. The option for a referral to a specialist at £300, but they'll probably just say they need to run further tests as well. I've already paid out nearly £5000 this year after Petplan screwed me over and it couldn't come at a worse time. Her breathing is laboured, her temp is normal, she hasn't lost any weight although she's very much off her food and the vet today did say there are signs of gum disease you wouldn't expect to see in a cat who's not yet 2. But at the same time, she's purry, using her litter tray, drinking and eating (albeit mostly dry food) and still alert and looking for a fuss.
I can't bring myself to even consider having her PTS without being 101% certain that it's the best option.