[pyrnet] Medical terminology usage re: dwarfs

[Patric Lundberg <pyrsrgr8@yahoo.com>]

Joe,

> ...a lot of misinformation out there.

Indeed.  Below I will go through a few issues I have with the way you
present some of the scientific evidence.  The things you say sound very
strong, and I'm not convinced you want them to be that way (forceful).

> ...scientific evidence of radiographical abnormalities in the
> vertebrae.

Before I go into any details, I just wanted to point out that this is a
logical necessity to create a smaller animal...  If you have a normal
size spine with only shorter legs, the resulting animal would look
really curious (and physiologically speaking, would likely have *a lot*
more structural complications than the present Pyr dwarfs).

> ...quote... having to do with Pyrs directly:
> "Radiographic abnormalities in chondrodysplastic Great Pyrenees are 
> restricted to the metaphyses of long bones and vertebrae."

When I read this quote two things strike me:  1) I don't inherently
remember where the metaphysis is located and 2) it actually sounds
rather minor from a physiological point of view...

To remedy 1) I went online to look for a picture describing where the
metaphyses of the long bones actually are located (it doesn't help
anyone if we don't understand the words thrown around), and found this
figure at Merck:  http://www.merck.com/pro/osteoporosis/inde206.htm

From the figure everyone can see that the metapysis is located away
from the center (called diaphysis) of the bones and the wider end-part
of the long bones (called epihysis).  The interface between the latter
and the metaphysis is where old bone is broken down and new bone is
laid down, what we call growth plate.

So, it is understandable that a dwarf (by definition) must have a
problem making enough bone to build long limbs, which is why the xrays
are interpreted as having "abnormalities" near those areas.

The reason I go into this with a generic explanation is that it can
sound really severe when we throw about medical terms that most people
are not familiar with.

The same xray can be described something like this:

"The growth plates in the long bones don't like they should in the
xray.  This would be expected as this a dwarfed animal."

With such a description, the condition no longer sounds very ominous.  
I'm not trying to minimize the issue, but it really bothers me when big
words are used to make something what it is not.

Now, for 2) - why do I say it sounds relatively minor?  Well, these
growth plate problems *only* occur in the long bones and the vertebrae
- this isn't really that terrible!  From a strictly biological
viewpoint, this is a very restricted problem - when a global biological
system is compromized, it is usually much more severe (poor
functionality in global gene products are typically developmental
lethals, ie the embryo doesn't survive).

Again, not to minimize the issue, in biological terms, the problem is
not a huge one.  As for the affeceted animal, I will let others with
personal experience define what is severe (I have only seen a couple of
dwarfs myself, so I'm no expert).

> ...Disorders that disfigure, maim or otherwise render an
> animal nonfunctional (i.e. cataracts, retinal dysplasia and
> detachment, chondrodystrophy). 

Again, a lot of big medical terms, sounding very severe.  I think it is
important to consider what both Linda and Kelley have voiced, that Pyr
dwarfs are typically not 'nonfunctional.'  Nor could the ones I have
seen be considered maimed (I get this image from a Mothy Python movie
of someone getting their arm lopped off!).

Yes, they are disfigured, but that comes by definition as a dwarf
inherently is not a typical-looking Pyr.

BTW, I usually disfigure myself every time I shave... ;-)

> The survey was antidotal.

While Peggy's survey may have countered some sort of effect, surely you
must mean anectdotal?  In fact, the survey probably was not designed to
be of any scientific use, but rather a recruitment tool (for if it was
meant to be a scientific survey, it was sloppy at best).

> The scientific literature refutes the results of same,
> as the survey did not find some the problems that science has
> documented.  

With the sample size presented, that would be the expectation.  Without
a comprehensive enrollment of statistically relevant numbers of
animals, I agree that it means little more than to serve as statement
to support an opinion.

> Now that we have identified the "deformities" we are now at a point
> that "oh, its not so much."  So lets tell everyone how much is OK to
> tolerate in the "Maimed and disfigured" dogs (not my words but DR
> Padgett's).

Two points here, firstly we were all aware what dwarfs look like - when
you made your statement using the word 'deformity,' I think the
objections again related to how strong is that word.

To a medical student, deformity is anything that isn't 'typical'
relating to an organism's structure (a slightly shorter pinkie would
qualify), but to a layperson it sounds like you are describing
Quasimodo.  

Secondly, Padgett used 'maimed and disfigured' to describe a whole
family of problems - you cannot say that those terms are true of all or
only some of the conditions listed.  To me, 'maimed' as used in lay
terminology does not apply to Pyr dwarfs and disfigured (as I explained
above) sounds too harsh to me.

To me, a Pyr dwarf is a non-typical looking animal which is an unlikely
candidate for the breed's traditional work and that may or may not
suffer complications from its condition.

Regardless of this, it also makes sense to me to work towards
elimination of the genetic reasons for their existence, which the GPCA
has done for a really long time.  While we wait for the solution to
fall in our lap (as most of us relegated to do), we can certainly
volunteer all verifiable information of which we know and donate money
(or time if they want your help) to the Health Committee.

My soapbox is now crumbling below me, so with this I shall keep quiet
for a while (sorry about the length).

Patric



=====
"Sage Advice Improves with Thyme"

Patric Lundberg, PhD
patric@pyrealm.com
Department of Virology
City of Hope National Medical Center
(626)359-8111 x2612

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