Thanks for all the advice!
Bailey normally eats either Purina One or Felix senior pouches, all flavours. Occasionally prawns as a treat. We haven't introduced anything new that could have caused this. He has a Catnip treat twice a day with his pill in it.
I've ordered some of the hypo-allergenic food from zooplus which is single protein (venison) Thankfully he's not a fussy eater so I imagine he'll like it. I'll limit him to that for the next 4-6 weeks and see if there's any change.
Kay, I'm confident it's not the felimazole as he's been on it for over a year now and it's only when we reduced the dose that he's started scratching again. If it was the meds, reducing it should have helped. Like you, I do wonder if the scratching was a side effect of the HT though and nothing to do with allergies. His T4 was within the normal range numbers wise when it was last tested (8 weeks ago), but I do wonder if he's still a bit hyper and thats why he's scratching. I've noticed he's obsessively grooming his front paws as well and his coat seems more prone to knots since we reduced the dose - exactly as it was before we treated the hyperthyroidism. Although I haven't found anything or anyone who's experienced this scratching thing in a hyperT cat.
Really hope we can get to the bottom of it, the last thing I want is the poor wee mite to end up with baldy ears and neck again. If changing food doesn't help and it's being on lower meds that's causing it I'll be at a loss. The last thing I want is his felimazole dose to go back up as I felt like I'd lost my cat. He barely moved and gained a dangerous amount of weight when he was on the higher dose. If it's not improved by our next vet visit, i'll discuss the possibility of changing to vidalta, perhaps a higher dose of it wouldn't zonk him out the way the felimazole did.