It sounds like ferret enteric coronavirus, ECE, but it COULD be
salmonella from the chicken along with it. Ferrets with ECE are very
susceptible to acquiring additional GI illnesses, and that combination
can prove fatal for some. Ferrets do not normally get salmonella as
easily as humans, but when compromised they do, and salmonella is
every bit as dangerous an illness for them as for us. They also are
just as susceptible as we are to a range of other food-borne
illnesses, some nastier.

So, since ONLY the lab at Michigan State can tell you if there is ECE
plus can find other illnesses your vet should use them for this
ferret.

http://www.ferrethealth.msu.edu

Use the ECE file in
<https://groups.yahoo.com/neo/groups/ferrethealth/files/Disease-specific%20files/>

And
http://www.miamiferret.org/ece.htm

And give your treating vet these links, too:
http://www.ferrethealth.msu.edu/Diseases/Gastrointestinal.pdf

http://www.ferrethealth.msu.edu/Presentations/

http://www.ferrethealth.msu.edu/Diagnostics.php

Most of the ECE studies are not free online, but:

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3381543/

http://www.sciencedirect.com/science/article/pii/S0042682206000365

And NO raw food for a ferret who is compromised, ESPECIALLY with a
GI illness. Reserve that for the well ones only, please. I have seen
far too many people accidentally kill ferrets with GI illnesses that
way. Okay, only about a half dozen people (though a few more ferrets
since three lost more than one) but that is way more than enough since
it is avoidable. (Also, follow recall reports on pet foods because even
though they are usually safer there are times when extra caution is
needed.)

[Posted in FML 8179]