Re: [pyrnet] Dwarfism or Congenital Chondrodysplasia

["Linda Weisser" <lmweisser@olywa.net>]

----- Original Message -----
From: <JGentzel@aol.com>
.
you only have to
scratch the surface and you find much information like I have reproduced
below. >>

I'm going to comment on some of what Joe has quoted here.  It is very
helpful to a broad understanding to know Mal people who have been through
this and have been deeply involved for years, and to talk to them about Mal
dwarfs and what and how they are.  Also to pay attention to what we do know
about Pyrs dwarfs.  Thanks to the recent work of Peggy Watson we know more,
and more accurately, than we have before.

<<Chondrodysplasia>>

Chondrodysplasia is ok, but it is more often called chondroplasia or
achondroplasia

<<This disease is
   neither "dwarfism" as it is commonly referred to nor is it dysplaysia
   (in the true sense of the word). >>

I have no idea how the authors define "dwarf" but this condition is called
dwarfism by absolutely everyone who deals with it, from breeders to medical
experts.  And it *is* "dysplasia" which simply means (according to
Webster's Unabridged) "abnormal tissue growth".  I was researching a heart
condition called "Tricuspid Valve Dysplasia".  The authors are "sloppy" in
falling into the "trap" that dysplasia only (or truly) means *hip*
dysplasia.

<<This debilitating disease is actually
   a birth defect causing the dog's upper foreleg to become overly
   massive, short, and twisted and appears in Malamute and related
   breeds. >>

Yes, it is a birth defect and beyond that it is a genetic birth defect.
(not all are).  The description ("massive, short, and twisted") makes all
dwarfs sound extremely deformed.  This is surely not true of Mals which is
the breed he is discussing.  The degree to which the dogs are affected
varies widely from hardly perceptible to extremely deformed.  Both ends of
the spectrum are just that--the outer edges.  I have no idea what he means
by "related breeds".

<<Malamute breeders were appalled by this condition when it
   appeared and immediately set out to eradicate it.>>

*Baloney* with a capital B.  Dwarfs existed for a lot of years in Malemutes
and were overlooked, excused, or explained as a form of nutritional
rickets.  Finally a breeder in WA state began to scream long and loud until
she finally got people to pay attention to her.  Yes, the Mals have a great
control program and pay a lot of attention (although less lately) but they
hardly "immediately set out to eradicate it."

<<   Steps were taken to locate these recessive genes. >>

Well the first steps were in discovering that these really were "recessive"
genes.  That took a fair amount of work to isolate.  A lot of this work
being done by and with Dr Ron Sande at WA State U, Pullman, who is still
the best resource on chondroplasia.

<<Most Malamutes today have been CHD rated.
   The percentage is the actual likelihood of CHD showing up in a
   breeding. >>

And this is possible because of many years of test breeding.  Test breeding
is still done but not often.  Most % are calculated on a computer with a
program designed to do this.


<<CHD may be diagnosed with various tests that include blood tests and
   x-rays.>>

It can be diagnosed by x-ray.  Simple carpal x-rays on pups under about 10
weeks old.  X-ray diagnosis on older pups requires more extensive x-rays
including of the spine.  Blood tests will not diagnose chondroplasia.  At
one point they identified a form of anemia in some Mal dwarfs and hoped
that this would prove to be diagnostic and with the best of fortune perhaps
diagnostic for carriers also.  Alas that all proved emphemeral and blood
tests and/or anemia are no longer considered useful.

<<I think it interesting that the condition is not a true dwarfism and is
certainly more that just a cute little Pyr, but has serious physical
deformities associated with the condition. >>

I would like to read these author's definition of "true dwarfism".
Dwarfism has many differing manefestations in different breeds and yet it
is all considered dwarfism.  Even pituitary dwarfism which is a hormonal
problem and results in what we would call in humans, midgets--small but
normal proportions.  And I agree that it is a lot more than a cute little
Pyr.  However, although the deformities may appear "serious" they most
often are not debilitating or painful.  Heck there are many breeds that are
dwarfs on purpose (dauchs, corgis, bassetts, Tibetal spaniels) and they
seem not to suffer excessively.

The information that Peggy gathered on dwarfs indicates clearly that these
dogs do not have unusual limitations (beyond being *very* short legged)
physically or in terms of their general health or temperament etc.  They
are very Pyrenean.  I am certain not recommending or even accepting the
breeding of dwarfs for any reason.  However, one of the first questions
that we get from people with dwarfs is --  how healthy will he/she be?  How
long a life?  Will the dog be in pain?  Do I have to euthanize this puppy?
Etc, etc.  We can with some assurance tell these people that the dwarf that
they love will probably be just fine.

 <<we work under the hypothesis that these
deformities exist with the syndrome in Pyrs?  Especially when it is
reported
to occur in some Pyr dwarfs.   >>

Again I ask, "*What* "deformities?"  If you talk to many Mal people they
will relay the same history of Mal dwarfs that we have of Pyr dwarfs.  A
health, active, busy life that is somewhat shorter than the average for the
breed.  No excessive medical problems.  And I also ask--"reported to occur
in some Pyrs" by whom and where, and can you share with Peggy this
information so that she can follow up on it?

Linda