Puppy Hair Loss

Question
We got a puppy in October (she was 3 months old). She is a toy poodle & boston terrior mix. We were told that she had a difficult time while weaning and went into shock because of low blood sugar. This resulted in major hair loss. I have taken her to the vet and he said that would not cause hairloss. She is still having problems with hairloss. She is up to date on shocks, has been wormed, and I even treated her for ear mites. I check her for fleas daily and have rarely found any. I bathe her in flea shampoo for pups when any is found. She doesn't go outside because we live in an apartment and she is puppy pad trained. What could be causing this?? The majority of hairloss is on her belly and up her neck, though she has some bald patches on the back of her legs, back, rear and ears. There is no sores or redness.She is a picky eater and will only eat poultry based foods. I should also note that she has very dry skin on her belly where the skin is exposed. I have tried treatment for hot spots etc. Nothing seems to work. I would greatly appreciate any advice you can offer.

Answer
I would culture the hair and skin for ringworm fungi and look for Malassezia yeasts.  That can cause what you are describing.  I would also have the puppy dipped for sarcoptic mange because those are common areas for the skin to be affected. In addition, I would add Omega3 fatty acids to the dog food for a couple of months to see if hair will regrow,  If all of that doesn't help, then a skin biopsy would be needed to look at the status of the hair follicles.