The way this question is written means that I’m going to have to answer it in two ways.

I’m going to have to be Jekyll and Hyde.

I’ll be Hyde at first, and you won’t much like that because I’m going to sound like an asshole.

In the second answer, I’m going to take everything you say at face value. I’ll be Jekyll (the nice one). I’m going to assume everything you say is 100% as it reads, and go from there.  

 ANSWER from Hyde:

Ninety nine percent of the time that someone tells me that they “have no idea what is going on” and have gone through more than two competent vets for a skin issue, and mentions the cost of the apparent lack of success all in the same sentence, it makes the hair raise on the back of my neck.

I wanna run the other direction.

It often means there are some major communication issues going on.

It means I have a person that won’t consider what I have to say, thinks I have an agenda other than helping their cat (read: money) and is frustrated because their pet has a skin problem that must be managed (i.e. no magic bullet cure).

And at the end of the day, they will blame me for it and just move on to the next vet. I’ve been there, done that, got the bad guy t-shirt.

Don’t get me wrong. In a vet appointment for a difficult problem, it can be completely overwhelming to be on the receiving end of a tonne of technical information headed your way.

I get that.

And I don’t pre-judge people. I have no idea what is going on in their life or what pressures they face. But over a decade into things you start to get really good at seeing patterns, details, and motivations.  

There is a two way street in every appointment, and people have to meet each other in the middle. For your cat’s sake.

Stay with me, this is going somewhere.

I just started watching Dexter.

Yeah, it’s been out forever, but with Netflix, a show that was produced a decade ago might as well be brand new. The only telltale sign of its age is that everyone uses flip phones instead of smart phones. In Dexter, it’s all about the details, patterns and motivations. That’s how they figure out “who dunnit”.

When I go all “Dexter” your question, I know that any vet worth his salt will never tell you “I have no idea what is going on” for a skin issue (or most issues for that matter).

That is rare (unless you truly ran into 2 vets in a row incompetent with skin disease).

It’s just not part of the vocabulary. “I don’t know what is going on” - that kind of talk is DRILLED out of us with our training.

They are much more likely to tell you “I have narrowed down this problem to these top 3 things - this is what you need to do to see which issue, or combination of these issues it is”.

You should be able to tell me what those things are on that list. And if you can’t, then I’m not sure where the communication is falling down here.

And in North America, several hundred dollars isn't enough to test for allergies, ear mites, fleas or other internal issues. Corners have been cut here that your cat’s scratching issue is hiding behind. And I don’t know who is holding the scissors.

Boy, don’t I sound like a complete jerk.

But if I’m right, and the above is true, then you’ve really got to find a vet you trust, demand a list of probabilities (you are spending the money - you must be getting at least this for your spend), and set your expectations right and consider that this is a problem you must manage but can’t cure. You gotta meet your vet in the middle. Your kitty will demand that you have regular visits to the vet. Your cat will never be an inexpensive one.

ANSWER from Dr. Jekyll

Sorry about Hyde. He’s a real ass, isn't he?

Let’s go through a few things in a bit more detail, because I know you don’t want this guy to suffer. These could be the rocks that haven't been turned over yet.

Your serum allergy test came back, and it’s true, your cat doesn't react to anything in the environment, so the chances of environmental allergy is low. Or maybe you did the skin testing instead, and nada. No response.

And you only did that after the two month food trial, with a diet certified to not have allergy stimulating residue. Or you went home made. And we know that serum allergy testing for food is like rolling the dice…it just spits out test results with very little meaning towards what is actually going on with your cats response to food. And you did this for two months….with no other treats that were off the menu…it’s hard, but you did it.

And we also know that skin scrapes…more than one…were done. And were negative for demodex. And these aren't those wimpy surface scrapes - you have to go deep into the follicles. You know this because your cat had little red rashes on the skin after they did them. I might have even told you he would look worse because of those rashes before I did the scrapes.

And then we stuck tape on your cat, pulled, looked under the microscope, and there was no yeast. Because yeast, when not caught, is itchy and horrible.  

And then we also know that your kitty has had no response to prednisolone, Atopica or antibiotics. Or maybe he does respond, but then it comes back, so we were sure to treat long enough to eliminate deep seated infection.

And there are no weird ectoparasites (Cheyletiella) flea allergy or ringworm (yes it’s not usually itchy but cats).

And your cat isn't hyperthyroid, or losing weight, or showing any other signs of internal liver or GI disease.

And sometimes, there is occult demodicosis. It doesn't show up on any of the tests. It’s just awful because these cat’s are just scratching themselves up and nothing else works for them (until they get their lyme sulphur bath…which is no fun).

And the leash he might wear isn't causing a contact reaction, nor is his food and water bowls.

If all of that is true, you really need a skin biopsy. In fact, sometimes I do a skin biopsy first, before I do any of the above. Why?

Because I’m never going to tell someone “I have no idea what is going on”.

If I ever look at a skin issue, and my own brain right away says “I’m not sure what that is’” then I'm going straight to biopsy to reveal the answer. I’m gonna fix that lack of perspective quick.

But I would never tell you that my brain said that.

Dr. Kris.