My Suzzy was getting a bald tail and I could not find any blackheads so I
thought adrenial problem.  I took her to the vet and he told me that some
times younger females went bald on the tails and to give her 6 months to
grow back.  I washed her tail and gave her feritone and in less then a
month she tail hair grew back.
[Posted in FML issue 2504]