Bless him

what about Piriton (nb not piriteze, that's a different active ingredient) if there is a possibility the itching could be allergic? Would need to be on vet advice, obviously, but might be something to consider.
I use a vets4pets practice and previously used a companion care, they're the same chain now. They are basically like a franchise, each practice is owned by one or more of the vets and they have clinical and financial freedom, they have to comply with certain branding/opening times/preferred suppliers etc and pay for back office services such as HR and accounting. So in that respect there will be excellent and not so excellent branches just like every other vets.
For me, working long hours during the week, it's a godsend, they are literally shut for 3 days a year and if you're a registered client, you can book weekend and bank holiday appointments at normal rate...and as you've found out, even if you do have to be squeezed in as an emergency, it's not as much as the out of hours!
Hope your little fluffster perks up quickly x