Our Keeshond is about to turn into a Mexican Hairless.
she has been losing a lot of hair over the last 6 months. The vet keeps doubling down that it's allergies, but she continues to lose hair along with frequent UTI's and ear infections. She's not itching/scratching. My wife did an AI search and AI suggested that it's likely a thyroid condition. Anyone have any experience with this?

That has not come up in discussions. How does that work? A blood test?

I think that's part of it. Our little toy fox terrier is showing some symptoms and the vet said she would have to keep her overnight for a full assessment.