[anonymous]

I would go along with the prescription food, if you don’t see improvement within a reasonable amount of time, I would ask for a referral to a veterinary endocrinologist, or find one on your own
It is best if you stick with one vet that you trust and listen to him. Versus hopping around
Just my opinion based on my experience.

For science based veterinary medicine go to skeptvet dot com I have found that site helpful. Often he answers questions. If I provide the direct link, my post may be removed.
Good luck