[QUOTE=everafterfarm;7852150]
We are on our second vet for the skin issues. I’m not against trying another. Mange was ruled out a long time ago. We are sure he has yeast issues as well, which is why I was so hopeful the thyroid meds would be the end of it.
Whether or not there is also something else going on like a food allergy, we don’t know. He is on a grain free food, but it is chicken based. I guess we all thought it would be “over” once we realized he needed the thyroid help.
The current vet I’m using said if the thyroid meds didn’t work his recommendation would be to take him to Auburn University(it’s the closest vet school to me).
I guess first order is to recheck his thyroid levels and do a skin biopsy even if one was done in the past. As for doing allergy tests, both of the vets I have used so far say it’s crazy expensive and often inconclusive.
My dog certainly feels much much better since he’s started the thyroid meds, and his coat came back shiny and beautiful, but it’s just now starting to be itchy again, and I can see a little bald patch in each armpit from the scratching. His past hairloss was his armpits and belly/genital areas. Also he stunk and you could see yeasty build up in the armpits. I don’t want him to get like that again![/QUOTE]
Yeast is often secondary which is why you see it with DM, allergies etc; it can also appear with skin irritation (eg excessive bathing, medical shampoos, chemical baths etc, etc).
As he responded positively to the thyroid meds, I’d start there, have his levels checked, Hemopet offers the gold standard on this :yes:
As for doing allergy tests, both of the vets I have used so far say it’s crazy expensive and often inconclusive.
I’m guessing that neither vet is an allergist 
You don’t need to do all the testing, start by booking a consult & understanding what’s happening with dogs & allergies, & how to manage this - even in the absence of testing/desensitizing protocols.
Easiest way to assess food allergies, is to switch to a raw food diet, as you can limit everything (any processed kibbles will always be subject to contamination (from the production lines), also the processing alters protein etc structure which can also increase reactivity).
Of course this means research & knowledge & commitment, so take your time to consider what you’re willing/able to manage.
Many dogs do improve with novel protein kibbles, so that is always a reasonable alternative.
Many “grain free” foods, apply an interesting definition of “grain” - perfectly legal for that product line.
In general, wait 2-3 month to assess food changes, though if you observe a negative impact, obviously discontinue.
Some dogs are also sensitive to the antibiotics etc that are used in commercial feed production rather than to chicken, beef etc.
(again going with a protein such as kangaroo or herring, often coincedentally removes the antibiotic etc
)