More recent: apparently, it is still not known if they get Lyme Disease.
http://fhl.sonic-weasel.org/browse.php?msg=YG12126
 
BTW, if you search under words like "ticks" you will find a number of
excellent vet posts on ways to prevent problems with them for your
ferrets at http://fhl.sonic-weasel.org .
[Posted in FML issue 4096]