This starts out with something I quickly sent last night then info is
added.

Could be a bacterial sinus infection or other respiratory infection.
Most likely influenza.

See these post from ferret veterinary pathologist, Dr. Bruce Williams:
http://ferrethealth.org/archive/YG4053
http://ferrethealth.org/archive/YG4054
http://ferrethealth.org/archive/YG10945

Note that he repeats that ferrets do not get colds. No one knows this
topic better than an expert in exactly the right area of study and
ferret pathology is exactly that.

Pharmaceutical companies would love it if ferrets could be used as a
model for human colds, but since they don't get the right virus
category they can't be. Currently, they are used as animal models for
influenza and at times for bacterial sinus infection (though not as
good a fit for that though they can trade some of them back and forth
with people).

It is not unusual for a human to have a case of influenza that is mild
for the person because she or he had a related one in the past (so it
can seem like just a cold) but the ferret will not have had a previous
exposure so the ferret gets a full-blown case.

Here is some info from a previous post I wrote:
When people think the ferrets have colds they instead have more serious
things, some of which need treatment, and some of which are responsive
to antibiotics (bacterial sinus infections are responsive to
antibiotics but colds are caused by rhinoviruses so are not). Ferrets
get bacterial sinus infections, they get influenza (especially avian
forms), they get pneumonia of several types, etc. They don't get the
rhinoviruses that cause colds which is great annoyance to the
pharmaceutical industry which would LIKE to study them in relation to
colds AND the human-overlap things that they do get but CAN'T because
they simply do NOT catch rhinoviruses.

See these expert vet posts:
http://ferrethealth.org/archive/YG4053
http://ferrethealth.org/archive/SG1618
http://ferrethealth.org/archive/YG10945
http://ferrethealth.org/archive/YG9530
http://ferrethealth.org/archive/YG4054
http://ferrethealth.org/archive/YG2137

Many people confuse bacterial sinus infections with colds.

If antibiotics work then obviously there is a bacterial infection
rather than influenza or another virus such as the colds that ferrets
don't get. If a "cold" seems to be going on unusually long in a human
then get sinuses checked for bacterial sinus infection. It's easily
checked and it's treatable though some strains are pretty hardy in
recent years.

Of course, some ferrets also wind up with allergies, but that is much
less common, and even fewer have sniffed debris into a sinus and can't
expel it, or grow sinus tumors, or have infected tooth roots infect
the sinuses. or...

Sukie (not a vet)

Recommended ferret health links:
http://pets.groups.yahoo.com/group/ferrethealth/
http://ferrethealth.org/archive/
http://www.afip.org/ferrets/index.html
http://www.miamiferret.org/fhc/
http://www.ferretcongress.org/
http://www.trifl.org/index.shtml
http://homepage.mac.com/sukie/sukiesferretlinks.html

[Posted in FML 6170]