To Nancy Hartman concerning vaccine reactions:
 
        I will defer the clinical aspects of this question to Dr. Brown, but I
can address what is going on with this ferret.
 
        Most likely what you are seeing, with collapse shortly after vaccination
and bloody stools is indeed a vaccine reaction, also known as immediate
anaphylaxis.  This is a very uncommon event in domestic animals, but it does
happen.  ( I have heard a number - approximately 1 in 10,000 cases attached to
several vaccines, but as that comes from drug companies, I don't know how
reliable that is.)
 
        For immediate anaphylaxis to occur, an animal has to be sensitized to a
component of the vaccine sometime previously.  When the component is re-injected
into the animal, a severe allergic response is initiated by certain cells in the
body which are primed to respond to that specific ingredient.  The cells that
are the trigger are mast cells, which line blood vessels.  When they are
stimulated by antibodies that have bound with the allergen - they release
chemicals that cause marked dilation and leaking from the blood vessels in the
area in which they are located.  They can also cause marked constriction of the
airways, furthering the distress to the patient.
 
        Anaphylaxis can range markedly in severity, from a small wheal or pain
at the injection site, to hives, to, as in this case, marked systemic vascular
dilation and shock.  Blood generally pools in the intestinal tract in ferrets in
shock, and often a small to moderate amount will leak into the lumen of the
colon, resulting in the passage of blood.  In no way should this be interpreted
as colitis, and it is generally a transitory phenomenon (if the animal
survives).
 
        Generally, if the animal is supported with fluids and some nursing care,
they recover fully.
 
        Vaccination reactions are an unfortunate fact of life for veterinarians.
 There is generally no way to predict which animals will be affected, unless
there is a history, as there is no in this animal.
 
        My suggestions would be to NOT vaccinate with the same product next
time.  A heavy dose of antihistamines may prevent a recurrence; I've used them
in dogs and horses in the past with a history of vaccine reactions to good
effect.  (Histamine is the substance the mast cells release upon unsuspecting
blood vessels...)
 
        Maybe Dr. Brown can enlighten us as to her experience with vaccine
reactions in ferrets....
 
Bruce Williams, DVM
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[Posted in FML issue 0778]