Steve and I are sorry that you are still having losses.  Has anything come
back, yet, from the pathologist?  What is being seen in the necropsies?
Those (especially the pathology done from the necropises since that will
allow for extensive tissue sampling that otherwise would be impossible) are
where you will have your best chance of an answer, of course.  Necropsies
and pathology are the most life-saving thing a person can have done in your
type of home situation.
 
I seem to recall that you said that you wanted cedar info even though you
figured it might be from a pesticide if the pathology supports that.  You
can find some cedar info at:
 
http://www.trifl.org/cedar.html
 
I checked in the _Handbook or Poisoning_ (an OLD book) for you and the
symptoms of pyrethrin poisoning (IN HUMANS) which that text lists are skin
sensitivity, and convulsions or coma.  It does not have checks for GI or
respiratory irritation, liver or kidney damage, or blood pressure drops.
Neither the livestock poisoning book nor one with picies list this
particular mum or its components.
 
From _Physicans' Desk Reference of Herbal Medicine_ (newest version -- the
most reliable source I included in my checking, again from humans but maybe
there's something useful here): "No health hazards or side effects ... with
the proper administration of designated Therapeutic dosages ... doses up
to 2 g ... are non-toxic"
OVERDOSE: "Headache, ringing in the ears, nausea, parathesias, respiratory
disturbances and other neurotoxic symptoms"
 
For treatment they have: " gastric lavage with burgundy-colored potassium
permanganate solution and installation of activated charcoal ... possible
cases of acidosis with sodium bicarbonate infusions ... in shock plasma
volume expanders should be infused ... monitoring of kidney function ...
intubation and oxygen respiration may be necessary" You will want to
discuss such procedures with your vet if that is the likely cause from a
medical standpoint.
 
I am not sanguine about your dropping of the infectious disease possibility
unless there is strong veterinary proof that this isn't the cause of the
deaths, and I urge you to PLEASE continue to hold off from interacting with
any other ferrets until it's sure that whatever is causing this is NOT
infectious; no one (including you) wants an epidemic if it's anything
infectious.  You also need to know this for sure even if all of them pass
away since some diseases remain in an area for extended periods of time.
 
I keep hoping for your stories to stop, since each comes with a death.
Maybe when the answer is found and the deaths stopped you can take a
breather and then write write survivors' pieces.
[Posted in FML issue 2911]