Debbie --
  You'll probably get alot of replies on this one!  Our ferrets have lived for
8 and 10 years respectively (i.e., two that died).  They certainly slow down
noticeably after 3-4 years of age, but they are far from senile!  How long
a ferret will live depends on many factors, some of them beyond your control.
I know that rabbits kept in inadequate cages are regarded as having a
lifespan of ~5 years, whereas pet rabbits of the same strains, kept in
more spacious quarters live for up to 15 years!  I suspect that the same
would be true of ferrets -- their longevity will depend on the conditions
in which they are housed.
   As carnivores, ferrets need pretty high protein food to thrive, but
this is hard on their kidneys.  Consider trying lower protein food for
them as they slow down -- this is commonly recommended for dogs.  Once
kidneys are compromised, you HAVE to use a low protein food, such as
Hill's Feline Kd.  One of our ferrets survived for over 2 years on
this (sometimes mashed in some low-salt chicken broth, for ease of
eating) -- which is two years more than she would have lived otherwise!
  In a variety of species (mice, rats, and probably monkeys), caloric
restriction increases lifespan.  This means giving a nutritionally
optimal diet, but 30-40% less than they would eat if given an unlimited
supply of food.  As far as I know, this has never been tried on ferrets,
so I do not recommend that you experiment on your pet!  I'd be interested,
though, if anyone on the FML has some experience with caloric restriction
in ferrets.  (If anyone is tempted to try this, don't limit the water!)
When it works, caloric restriction in infancy leads to a smaller adult;
you get most of the benefits (in terms of lifespan) starting after
adolescence, though.
  I hope this helps.  Best of luck.
 
  Bob Reis  ([log in to unmask])
[Posted in FML issue 0981]