Melissa Durfee asked:
 
>What is the normal reaction to a vaccination?
 
The "normal" reactions range from none at all to a life-threatening allergic
reaction.  The latter are rare but have been reported in ferrets receiving
any of several vaccines.  The rate of severe reactions varies (1) with each
vaccine, (2) with the vaccination experience of the animal (you need to be
previously exposed to a vaccine before you can react to it, so severe
reactions never happen upon a first exposure), and (3) with the genetic or
immunologic predisposition of each animal.
 
It is very important to note that there can be normal reactions that are
part of the body's immune response to the vaccine.  I can't make a list of
which reactions are normal and which indicate a severe allergic response
because that varies with each vaccine.  For Fervac-D, the vaccine consists
of a so-called "modified live" virus, which has been adapted over many
growth cycles in the lab to infect chick eggs and not ferrets.  The vaccine
actually "infects" the ferret when it is vaccinated but it has almost no
chance of actually causing distemper in your ferret because the virus in the
vaccine has been modified to grow in chicken cells, which belong to an
entirely different taxonomic class of animal.
 
Following a vaccination with a modified live distemper virus, any severe
reactions seen within the first hour are likely to be allergic reactions and
a vet should see the ferret at once.  These reactions include convulsions,
shock or torpor, bluish-purple blotches spreading under the skin, sudden
anemia (look at the gums) combined with shock...I'm probably missing other
symptoms, but you'll *know* something is wrong, and it will happen within an
hour or so of the vaccination.
 
Then there are the delayed reactions.  Some people have interpreted these as
severe allergic reactions but most of them are not at all.  Anything
resembling flulike symptoms that begin half-a-day or so after the injection
probably means that your ferret's body is mounting an immune response to the
vaccine.  (That's why you vaccinate them to begin with.) These responses
include, shivering, lethargy (*not* torpor, just usual tiredness or
sleepiness); even vomiting may be part of the normal response if it follows
the vaccination by several hours.  If these flulike symptoms don't go away
within a day, then call your vet, but otherwise, it means that your ferret's
body is fearing up to battle the virus and whipping the immune system into a
frenzy.
 
It is worth noting that there is always a slim chance of so-called
"breakthrough" infection with a live virus, such as some kids in the 1950s
who actually caught polio from an injectable modified live polio vaccine.
You make that decision on your own...take a *very* tiny risk of your ferret
getting distemper from the vaccine, or fail to vaccinate and take a 100%
risk of your ferret dying if it is ever exposed to distemper.  You don't
have to be a statistician to make that choice.
 
Other vaccines don't always produce flu-like symptoms depending on how
they're produced.
 
Finally, returning to the lymphoma thread, I've spoken with United Vaccines
and they *do* screen the chick eggs they use for freeloading microbes.  I'm
getting a copy of the procedures they use to screen for contaminants which
I'll run by the virologists at the university.  So, that puts vaccines low
on the list of ways to transmit the purported lymphoma virus.  The most
likely route of transmission now appears to be ferret-to-ferret (called
horizontal transmission by us infectious disease types) within households,
possibly complicated by genetic susceptibility (one of the households of
ferrets studied by Susan Erdman had more cancers in pandas and DEWs but not
in other households, so it may vary by breeder or be a spurious association).
So, I'd exhort those who have had multiple cases of lymphoma among their
ferrets to try to think whether the ferrets who got cancer had anything in
common compared with other ferrets who didn't get lymphoma.  The knowledge
to stop the spread of this virus may be out there.
 
--Jeff Johnston ([log in to unmask])
[Posted in FML issue 1726]