This is such a touching story!...I'm so glad your husband was so willing to intervene in helping this pup.....I'm so glad this worked out for everyone. It sounds like you both will give this baby much needed love and care.
As a side note, causes the hair loss could be caused my many things but one of them *could* be hypothyroidism. One of my boys had it but the vet said he didn't. After reading some of Dr.Dodds articles I insisted they run a 5 panel test and sure enough he was hypothyroid.
This is some info....
Dog Hypothyroidism Causes and Treatment | Natural Remedies for Canine Hypothyroidism
Good luck and I wish you all the best!