In addition to everything people are offering here, you might want to find a new vet. It’s bizarre that they apparently haven’t suggested anything to you about allergies given the saga you described.

You can also try a clay-free litter like Feline Pine. It’s made of compressed sawdust pellets (like for a BBQ smoker) that swell and fall apart when they get wet. You need to develop a very different scooping technique with it though. Get a scoop with larger holes to let the pellets through and grab poop. Ideally get two litter trays that nest, and drill a bunch of holes in one. Leave them nested, then lift the inner and shake to let all the used/wet sawdust fall through, like a colander, and pour it into a trash bag.

I get it at Costco for about $64 for 30 tablets, which is 4 months when you’re using a pill cutter! But my dog is small and can have a dose of 1/4 tablet for a large dog. If you have a large dog then that’s no good. (But all cats are small so OP could go my route)

You can also talk to your vet about Apoquel. It’s nominally only for dogs but it’s sometimes used for cats. It’s kind of expensive, but is the same cost per pill at several different dosing strengths. So if you do go that route try to get your vet to prescribe it at a level where the dose is 1/4 tablet and buy a pill cutter.

One action you could take as a mod is adding a clear rule in the community sidebar about bots/AI slop. As a plebeian, I don’t know whether I should report a suspected post, or how to categorize it if I do. Is it spam? “Breaks community rules” is at least an easy choice if there is a rule about it. Nice plebs don’t want to flood mods with questionable reports.

I appreciate you doing the web search for me! (No /s)

What a strange standard to have!

This sounds like it also partially explains why a sixteen penny nail is written 16d. But not why pennies are somehow used to describe nail sizes.