One thing to take into consideration: DO start the old age exams and
tests earlier than for others with any neural crest variant ferrets.
One repeated topic of conversation on the FML and in Ferret-Genetics in
Yahoogroups has been about how many of the neural crest variant ferrets
develop problems at earlier ages and how many have had a somewhat
shortened life span compared with other ferrets so this is just a logical
health precaution.  What you would have started doing at 6 in medical
care do instead at 5, and what you would have started doing at 5 start
instead at 4 just to be safest.  You can find these past conversations
in the Archives.
[Posted in FML issue 4565]