SO sorry to hear about your baby
When my Bailey had some severe biting issues and his hair was gong in spots because of this, I found out that he was allergic to anything to do with fowl: turkey and chicken. A lot of foods have fowl in some form
Since he has been on allergy food, his hair has grown back
It was so hard to watch him always itch... but now he is all better. They sent me home with the new food and some Benydrl. If you use Benydrl, search this up, as there is some info on the amounts to give per pound. I sure hope that you find out what's wrong. Cheers!