If a ferret has a lot of plaque build up and/or infection in the gums there
is a lot of bacteria present in the mouth.  When he then breathes in he is
inhaling this bacteria into his lungs.  It can affect the heart/lungs over
a long period of time (same as with cats + dogs) so it is advisable if you
use a toothpaste rather than wait until there is a plaque build up.  If you
get an enzyme based toothpaste there is no need to actually brush, just
wipe it on their gums or on a paw for them to lick off.  It works by
breaking down the bacteria in the mouth + prevents plaque build up.  Most
vets should stock some but the trade names will probably be different
depending on where you live
[Posted in FML issue 3440]