We have three ferrets with the tatoo on the ear from MF, and BELIEVE ME,
they hear just fine.  The other one we have, Sharkie who doesn't have a
tatoo IS deaf.  You can't assume a tatoo means medical problems.  Tatooing
could be just to let you know they are neutered and descented, they are
from a certain breeder, but it doesn't always mean deaf.  Like I said we
have three with that tatoo and they all hear just fine, they are so perky
and alert when they hear something.
 
Bob
[Posted in FML issue 3217]