Re: [pyrnet] Dwarfism or Congentile Chondrodysplasia

[JGentzel@aol.com]

I reference us all to the following post from Linda a couple days ago:

<<Well, I don't know who has been telling you that but sometimes I think that
there are a lot of loose lips around; some trying (deliberately or not) to
obscure what is going on here.  Trying very hard to make it, or pretend
that it is, something other than what it is.  I am not saying that
chondroplasia in Pyrs is *identical* in all particulars to what we see in
Mals but in most parameters, they really are the same.  Including their age
and health profiles and the skeletal changes seen radiographically, many of
which are used to diagnose the condition.

I have a problem understanding why anyone would wish it to be different
from Mals.  If we have basically the same condition, we can benefit
immeasureably from what the Mal club has accomplished over the 20+ years
that they have been working with the condition.  We won't have to reinvent
the wheel.

Linda Weisser
lmweisser@olywa.net>>

I totally agree with Linda's last paragraph and agree that the experts who 
have looked at this have all seemed to opine that the Pyr has the 
Chondrodysplasia form of dwarfism.

In an effort to gain some more information about the process to see if what I 
had been told and understood about deformities was valid, you only have to 
scratch the surface and you find much information like I have reproduced 
below.  


Chondrodysplasia

   Chondrodysplaysia was discovered around 1930-1940s. This disease is
   neither "dwarfism" as it is commonly referred to nor is it dysplaysia
   (in the true sense of the word). 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. Malamute breeders were appalled by this condition when it
   appeared and immediately set out to eradicate it.
   
   Steps were taken to locate these recessive genes. By breeding an
   unknown dog to a known CHD, the pups were then rebred to CHD dogs and
   percentages were calculated. Most Malamutes today have been CHD rated.
   The percentage is the actual likelihood of CHD showing up in a
   breeding. Malamute breeders tend to agree that 6.25% (one
   great-great-great grandparent is a carrier) is the upper limit of
   acceptablity in a CHD rating.
   
   Puppies are CHD rated now by taking the CHD factors of both parents
   and averaging them together. Example:

   Dog       1.75%
   Bitch     2.01%
   ---------------
   (1.75 + 2.01)/2 =
   puppies   1.88%

   Needless to say, an non-CHD certified Mal or a Mal that is certified
   above a 6.25% should not be bred, in order to contain the disease.
   Non-CHD certified dogs can be CHD certified, but it is a very
   expensive procedure.
   
   CHD may be diagnosed with various tests that include blood tests and
   x-rays.
   
   _The Complete Alaskan Malamute_ by Riddle and Seely covers this
   disease fairly well.


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.  There is a lot more information, 
but should not prudence dictate that 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.   

Joe