Matt, kits need to have vet check-ups, anyway, and be gotten on their
schedule for the rest of their canine distemper vaccine kit series (3
as kits, specially timed) and later their rabies shot as well as having
initial health exams, so make an appointment.  You can find URLs of the
lists of ferret vets by going to the crit refs in the menu on your left
at http://www.ferretcongress.org.
 
Meanwhile, stop the milk.  Call the store or breeder and find out what
was fed there then mix it with water and feed the same food.  Later you
can slowly introduce other foods along with the food the kits are used
to.  Because they are vomiting dehydration is going to be a real
concern.  If dehydration occurs or other worrisome signs happen (like not
defecating which can indicate blockages) they need vet care right away.
Are they defecating?  Have you ferret-proofed so that they won't get
blockages?  Blockages can be quickly fatal.  ECE is always possible
though kits usually show fewer symptoms than adults so I suspect it is
either the food, something else ingested, a virus (They do get influenza
and if trouble breathing is among their symptoms they need vet care
pronto.), etc.  If you are new to ferrets did you first read useful
guides like _Ferrets for Dummies_ which is very handy for anyone or
Ferret Central at
http://www.ferretcentral.org ?
i Also, do read about ECE at and more at places like
http://www.afip.org/ferrets/index.html
 
Becky, you will find a LOT about adrenal neoplasia in
http://fhl.sonic-weasel.org
with my personal favorites being by Dr. Jerry Murray (Search from as
AFERRETVET.), in the FML Archives (addy in the header of every day's
FML), and in the URLS to be found in the crit refs at
http://www.ferretcongress.org .
 
Blindness is not at all uncommon.  Their primary sense is smell.  If
you go tot he sonic-weasel addy you will find almost 60 posts on it,
with folks questions and answers.  Here is a useful technique:
http://fhl.sonic-weasel.org/browse.php?msg=SG6329
 
Training to not bite or nip ( Biting FAQ ):
http://www.geocities.com/SoHo/Lofts/1083/probintro.html
We've trained a number of problem ones and what are needed most often
are; no physical punishment (as in no hitting and no flicking or you can
undermine trust), consistency (something which can be a problem for those
who are focused in tightly on chore when a "notice me" or a grooming nip
happens), times out, making sure there is no medical problem (usually
dental when a kit bites from our experience with a painful entrapped kit
tooth or difficulty teething -- the later of which is helped by Foamy
Fries or Chew Weasels in moderation), and studying the context of bites
to better understand the ferret's history and devise ways to reassure the
ferret that the bad experiences of the past are over.  They DO learn that
humans can't take play bites like the ones they gave other thick skinned
kits when they get times out when they over-do it.
[Posted in FML issue 4386]