This post has been reduced due to space constraints.  The full text may
be found at the FHL site.
 
Dr. Bruce Williams in FHL Digest 57 discussed ECE particulars, complete
with a fascinating Helicobacter note in relation to GI pH and disease
susceptibility:
 
>Will you please tell us how you identified the reason (causative agent)
>why ferrets come down with ECE.
 
I have taken the liberty of posting the abstract of the article in the
August 15th issue of the Journal of the American Veterinary Medical
Association in which we described the findings associated with
approximately a three year investigation on ECE in ferrets.  For those
who are interested, it is in the files section.  (Or also for those whose
vet's may not be totally up on their ferret reading.)
 
The virus was identified in the feces of animals acutely infected with
extracts from feces of animals from several facilities undergoing
epizootics of diarrhea.  Similar epizootics were seen in the laboratory
following inoculation.  The patterns of outbreak strongly supported a viral
origin.  The lesion seen in the intestine of these animals was very similar
to that seen in dogs, cattle, and rats with coronavirus infection, so that
was the first clue.  Very characteristic coronaviral particles were seen
via transmission electron microscopy of feces and intestinal tissue of
acutely infected animals.  When culture of this virus proved elusive (as
is characteristic with this family of viruses, we developed a monoclonal
antibody to identify the presence of specific coronaviral antigen in the
enterocytes of affected animals.  The antibody proved exceedingly specific,
identifying with 100% accuracy animals which were involved in outbreaks,
as opposed to negative controls taken from before the first outbreak of
coronavirus was seen (1993) or those with either normal tissue or other
definitively diagnosed enteric disease.  The combination of appropriate
lesion, virus visualization, and identification of antigen is sufficient
to establish this diagnose, however until we are able to grow this virus in
culture, it will remain a "coronavirus-associated"disease due to current,
but somewhat outdated nomenclature standards in the veterinary community.
 
>How did you come to the conclusion that the causative agent is a
>"coronavirus'?  And just what is a this?
 
Coronaviruses are a family of virus that affect numerous species of
animals.  Enteric coronaviruses affect dogs, mink, cattle, cats, rats,
mice, swine, and man, usually causing diarrhea and occasionally death.
 
>nutrition may play a more than previously thought impact on the
>development of this condition
 
Indeed, I do believe that, although it has yet to be characterized.  A very
plausible theory which might explain the increased severity of coronavirus
infections in older animals, and the rather inapparent lesions seen in kits
is the fact that coronviruses appear to have trouble establishing infection
in a low pH environment.  A older ferrets often have concomitant
Helicobacter infections, which result in a higher (more alkaline) gastric
environment, this may be a contributing factor as to why they appear more
significantly affect (in addition to the fact that they often have other
concomitant disease).
 
>In spite of the fact that we are in receipt of many different ferrets,
>of all ages, in various states of health and nutrition, we've never
>experienced a case of ECE.  Why?
 
That I can't answer.  But I have heard it before, and I have also heard
back from a number of people when it did hit, and they were faced with
tremendous morbidity.
 
>Airborne transmission of viral particles here would be so very, very easy.
>Yet no ECE.
 
Indeed, yes it would be ripe for transmission of many viral diseases.  Not
that all operations should be designed to ward off viral disease, but
operators in such facilities should certainly be cognizant of the signs
of viral diseases and ready to act should the possibility of an outbreak
exist.
 
>staple which is fed to keep the ferrets from getting sick, or more to
>the point, to ensure health.
 
Your claim proceeds on the assumption that they have been challenged with
the virus, which we do not know.  There are still quite a few facilities
which have not seen ECE - it is common, but not ubiquitous in the U.S.
 
My knowledge is not of nutrition, but of the virus.  I would imaging that
no diet would render an animal immune to the actions of this virus - to the
invasion of villar enterocyte, the necrosis, of same, and the reparative
process of the gut - all of which contribute to the clinical signs.  While
you may have found a preventative to ferret coronavirus infection - it is
apparently a multifactorial solution given in the absence of evidence of
challenge.
 
With kindest regards,
Bruce H. Williams, DVM, DACVP
 
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[Posted in FML issue 3356]