I have two male ferrets, one MF and one Path Valley.  The MF ferret is
about 2 1/2--we've had since June, and he's thin.  His coat is coarse and
thin, hasn't changed a bit for winter.  My PV ferret has developed a
beautiful soft, thick fur coat, and also gained some extra weight (classic
pear shape!).
[Posted in FML issue 2515]