Ferret kits need to be vaccinated against distemper at 8 week as well as at
12 and 16 because the immunity that they get to distemper from their mother
only last about 6-8 weeks.  The immunity only conferred during the first
feeding and not the entire time the kits are nursing.  If they are not
vaccinated until 12 weeks they have about a period of 4-6 weeks when they
have no immunity.  However, at 8 weeks of age their immune systems are not
mature enough to effectively deal with the vaccine and hence two more
boosters are required.  This explains why an adult with an unknown
vaccination record only needs two shots at 3-4 week intervals, while kits
need three.  So no, it has nothing to do with a hang over from cats and dogs
it has to do with how the immune system works.
 
Carolyn McColl
Division of Life Sciences
Department of Endocrinology and Immunology
University of Toronto at Scarborough
Scarborough, ON  M1C 1A4
[Posted in FML issue 1905]