Regarding mycobacteriosis (tubuerculosis) in ferrets:
>The ultrasound and biopsy were done yesterday and upon calling for the
>results today, the vet informed us that no cancer cells were found in the
>biopsy but that a micro bacterium was found in a smaller mass found near
>her stomach.  (Biopsies were taken from both masses, the liver and the
>spleen - spleen showed up enlarged on the xrays).  The results indicate
>that the bacterium may be of the tuberculosis family and the vet is highly
>concerned that it may be the form transmittable to people.  The vet is
>scheduling surgery with a ferret-specialized vet for removal of the masses
>and culturing of the tissues to determine if it is TB and, if so, the form
>transmittable to humans.
 
I have seen several cases of Mycobacterium in ferrets - they have all been
identified as Mycobacterium avium-intracellulare, a type that generally,
only the aged, infants, or immunosuppressed patients can get.  This is not
the "human-type TB" which most of us think of.  We normally come in contact
with this bacteria every day.
 
The bacteria that causes the classic tuberculosis is Mycobacterium
tuberculosis, which causes a chronic pneumonia in people that can spread to
other organs over time.
 
While M. avium can be a debilitating diarrheal disease in ferrets (in most
animal species, it affects the GI tract, not the lungs, and it is difficult,
if not impossible to treat (I have talked to one owner who tried via IV
antibiotics), the public health concern is minimal, and the disease does not
generally necessitate the euthanasia of the ferret after diagnosis.
However, development of a wasting condition over several months and eventual
euthanasia due to debility is a very real possibility.
 
>Since human-type TB is transmittable via the air, the vet is highly
>concerned because if the cultures come back as human-type TB, many, many
>people will have to be tested for it .
 
The chances of it being the tuberculosis bacillus are minimal at best - it
has never been reported in ferrets.  The mode of transmission of M. avium,
because it infects the GI tract is fecal-oral, rather than respiratory.
 
>We're talking *hundreds* of potential exposures.  Now, we won't know for
>sure until after the cultures are done and I won't know until tommorrow
>when the surgery can be done.  The vet was optimistic and said it may be
>simply a ferret-type form of TB or a form of TB only applicable to Sasha,
>or it may not be TB at all, BUT, he was terribly concerned about getting
>the cultures done ASAP.
 
No reason for you or your vet to panic - I don't think anyone will need to
be tested.  No one has ever contracted this disease from a ferret, at least
in my experience.  The surgery is a good thing to take out the infected
node, and get a positive diagnosis.  Removing infected nodes may also
increase potential life span, but it is doubful that you will get all fo the
bacteria - there are usually some present in the intestine as well.
 
One concern is your other ferrets.  We don't know that much about the
pathogenesis of M. avium in ferrets, and Sasha will be shedding in large
amounts.  It would be prudent to keep her in a separate cage - while regular
contact with the other fererts probably doesn't pose a lage risk, contact
with Sasha's feces, which have a much higher concentration of the bacteria,
should be avoided.
 
Bruce Williams, DVM, DACVP
[Posted in FML issue 2213]