Well, Wolfy asked for an audiologist on the list to address this issue.
And, since she just learned today (from ME!) that I am not the only
ferret-owning audiologist in New England - and on the FML - I must
assume she is talking about me (again!). So, here goes a little bit.

Wolfy wrote:
>The odd little behavior nicked named the "Pez head" movement is not
>seen in all deaf ferrets. I'm not even sure if it's seen in the
>"majority" of them, but it is seen frequently. By no means should
>it ever be considered an indicator of deafness. It can be dangerous
>to make that assumption because a similar movement can also be
>indicative of something seriously wrong such as a neurolgical problem
>or a disease process.

My response:
Well, Wolfy has seen my Rocky Bobbles, who had a neurological problem
and was also deaf. He had NO control of the neck when he was not
upright and his head literally bobbled around. I have had several other
deaf ferrets and NONE of them has had this problem. It was always
attributed to neurological damage. What I DID attribute to his deafness
was the fact that he loved to sleep in the middle of the room with no
covers and not curled up. He would stretch out on the floor; I assume
it was so he could feel the vibrations that were present when people
walked. It was his security. I have had other people tell me their deaf
ferrets did that, too.

Then Wolfy said:
>I'm not sure who coined the word, but I do know that many years ago
>several deaf ferret owners started to use the phrase to describe the
>funny little behavior that deaf ferrets can exhibit. It's purely
>anecdotal. And there is surely no scientific data backing it up
>whatsoever. As to the why of it all, perhaps an audiologist on the FML
>could answer that and share all of the possible reasons as to why a
>deaf ferret would do this. The behavior might not just be caused by
>deafness, but it might be caused by something to do with the anatomy
>of the ear in a ferret that has a neural crest genetic defect.

My response: Well, the vestibular system and the auditory system are
linked together. The vestibular system is the balance system and the
auditory system is the hearing system. The eighth cranial nerve has two
branches - the auditory branch and the vestibular branch. They occupy a
very small space and sometimes a problem in one area can cause symptoms
in the other. Because the derivation of the audio-vestibular system
from specific embryological areas from which other body parts also
come, it is possible to see some of the same physical problems with all
animals (even the human ones) who have a specific genetic defect. Many
of the syndromes that are present also have some muscular weakness. It
may be that the ferret has a problem supporting his head because the
muscles are weak, or it may be that the nerves are just not firing
properly. Without appropriate testing, it is just possible to know.
And, the truth is, we are not doing any type of genetic testing on
ferrets - at least not diagnostically.

So, Wolfy commented:
>What I have more commonly seen are deaf ferrets who love to flip there
>heads back and watch the world upside down.

And, Jacci chimed in:
>The only weird thing she (Skye) does that I've wondered if other deaf
>ferrets do is when you pick her up & are holding her like against your
>chest, she throws her head completely back so that she is looking at
>everything upside down.

Yup, Rocky did that, too. BUT, he was the only deaf ferret I had who
did that. Again, I attribute it to more than just being deaf. I would
love to know several things about the ferrets doing this - color,
patterns, eye color, blaze?, bib?, stripe?, gender, face shape, etc.,
etc., etc. Deafness is not a disease. It is a symptom of something
else. If it is the result of a neurological problem, there may be
other symptoms evident.

Ya know, since many of these ferrets come from Marshall Farms, it would
be interesting to see the lines from which they were descended. It
could be that some of these animals are produced by breeding pairs that
are perpetuating the problems. What is that commercial? You get your
traits from your grandpa and your ma and . . .

-- 
renee :)
It's amazing how much can be accomplished if nobody cares who gets the
credit!
"The most effective way to do it, is to do it." Amelia Earhart
Ferret Emergency Response, Rescue & Evacuation Team (F.E.R.R.E.T.)
http://www.ferretemergency.org
[log in to unmask]
International Ferret Congress
http://www.ferretcongress.org
American Red Cross
http://www.redcross.org

[Posted in FML 5722]