My little doxie is losing...

Question
My little doxie is losing her hair. She has naked ears and her chest,and
tummy are bare.  She has one spot on her neck that looks a little like
ringworm but we have treated it and it seems to have healed, but the hair
has not come back.  the spot is a little smaller then a dime and it's been
there for at least 5 months.  It is the sight of her puppy shot.  It looks
like the hair
on her hind quarters is getting very thin now
I saw the owners of her dam today and they told me the same thing is
happening to her Mother and one of her brothers.  

Answer
I would recommend having her Thyroid checked as hair loss and slow hair regrowth is a symptom of under active thyroid.  If you are noticing any increased thirst or urination, then I would recommend a chemistry screen to check for elevated ALKP which can indicate Cushing's Disease.  If all the tests are normal, then I would be concerned about seasonal alopecia, which sometimes responds to melatonin but the hair loss is usually along the sides of the body not where you describe.