From:
"ncferretmom"
Date: 2008-01-27 02:46:37 UTC
Subject: [ferrethealth] Re: New kit ear pictures now online
To: ferrethealth@yahoogroups.com
Jane, I am an audiologist who recently made a presentation on the
development of the ferret ear. Typically, ear canals open at end of
first month (Moore, 1982; Kelly et al.,1986. By postnatal day 29 the
most proximal parts of the external auditory meatus (EAM; ear canal)
open, but are filled with mesenchymal fluid. It is not usually until
about day 32 that the EAM opens. So, there is no behavioral response
to sound and no acoustically influenced neural activity before about
day 30.
We know that in humans, children who are deaf from birth will begin to
develop speech (vocalizations) and then lose them when they do not
receive auditory feedback. At least in ferrets we observe that they
continue to vocalize even though they do not appear to have any
noticeable hearing.
In a week, these kits would begin to demonstrate responses to sound.
Danee has shared her observation that the mother's vocalizations seem
to be directed at her kits at about the time they are able to hear her.
Hearing loss resulting from trauma would need to be a physical trauma,
not an emotional one. I am unaware of any psychological or emotional
trauma (such as would be on the level of spay/neuter) causing a
hearing loss. There are some examples of humans with central deafness
or hysterical deafness that have no physical cause. Primarily, though,
it is the result of genetics, physical trauma to the ear or auditory
nerve or the result of exposure to high fever, ototoxic drugs or
bacterial or viral infections. Unless there is a reaction to
anesthesia or the ferret reacts to the medications used, I would doubt
that it would be likely to develop a hearing loss at this stage as a
result of the spay/neuter, de-scenting and removal from their mom.
In terms of the ferrets, however, there is nothing to provide us with
the information to prove or disprove this. I have not searched the
literature to determine if there is anything out there about other
animals, though. And, I defer to others who may be able to provide
information on the long terms effect of anesthesia on the developing
auditory system of the ferret.
I hope this has been of some use to you.
Renee
--- In ferrethealth@yahoogroups.com, Jane Bradley <flamingolady@...>
wrote:
>
> It these ferrets were going to sold through a pet store, in another
> week to 2 weeks they would be spayed/neutered and de-scented and
> removed from
> their mother's care. I know that deafness is usually due to genetics
> (breeding for certain colors, albinos) but what about the trauma they
> are put through at the time when their hearing is just developing?
> Couldn't this also contribute to some of the numbers of deaf ferrets?
> Jane
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