>... I'm sad to post that there's a good chance that my Rocket has adrenal
>disease.  He is showing the classic hair loss at the tip of the tail.  The
>rest of his tail is only covered by guard hairs (no undercoat) which come
>out easily if I pull lightly.  The tip is almost completely bald, and I'm
>sure it will be no time before the entire tail is hairless.
 
While there could be an adrenal contributing factor most case of ONLY the
tail losing fur are NOT from adrenal disease.  If you had said that it was
on the lower back just above the tail then that is one of the signature
places, though any bilateral trunk, foot, or top of head fur loss can be
from adrenal disease.  What you describe sounds like it might be what is
commonly called "rat-tail" on-line  (Think Russ began that term as more
than just a description, but not sure.), a dermal condition as common to
them as acne is to human faces and backs.
 
Most likely you will told to wait and watch since it might not be an
adrenal growth, to meantime try one of several possible medicated shampoos
or wipes.
[Posted in FML issue 3525]