Canine Fungal Infection Can Thyroid Issues That Cause Canine Hair Loss Be Treated With Something Found In The Pet Store?

Can thyroid issues that cause canine hair loss be treated with something found in the Pet store? - canine fungal infection

I have an adorable little Peekapoo, has lost much of their hair and had parts of the skin, laboratory testing of fungi and bacteria in the blood ... Thyroid looked like a possible cause, but since I maxed my credit card for veterinary bills, I was expecting something Economic / OTC avoid the training. I love my dog and I just want to get well. :)