Re: [pyrnet] Pyr eyes

[darrell goolsbee <dgg@star-telegram.com>]

<<I do not disagree about the very serious nature of PRA.  My remarks
> were
> directed at Juvenile or late onset cataracts.  This condition (JC)
> rarely
> leads to disability except some minimal in very late life i.e. 10
> years or
> so.  I speak only of Pyrs, I claim no knowledge of other breeds
> sequelae.>>

I don't know that I would put cataracts in quite the same class as PRA,
either. But I think the same principle applies. From research I did for
a recent eye article in our local club publication, a rule of thumb is
that cataracts are likely inherited if they manifest at 6 years or
younger and are found in both eyes. True late-onset cataracts, like at
10 or so, may well not be inherited but a product of the aging of the
eye. The younger the onset of the cataracts, the greater the possibility
of blindness as the dog ages. It is potentially a very serious disease,
but I will admit that I do not have enough info about Pyrs specifically
-- i.e., at what ages are we seeing cataracts in Pyrs?  If we are seeing
cataracts in young dogs, or dogs in their prime, we should be quite
concerned about it.


<<I would probably concur with PRA.  To me there is nothing more serious
> than
> Dwarfism to the breed itself and that is not intended to diminish the
> serious
> nature of PRA that you speak of.  It, Dwarfish, is much more serious
> as it
> has infested the whole gene pool essentially, where PRA we might have
> a
> change to limit it greatly with early education and an open honest
> provision
> of information.>>

We do have an opportunity to limit the spread of PRA, and some other
diseases, too. But for this to happen, testing must be done. PRA is
NOWHERE near as widespread as dwarfism. But imagine for a moment if it
were. The effect on the breed would be far more devastating than
anything we have seen with dwarfism.

<< SAS sounds extremely bad as well and its inheritance mode of a
> problem.  What
> is the feeling of knowledge presently out there on SAS puppy, if both
> parents
> must be carriers?  Or can only one transmit the disease forward.  We
> really
> do not understand the nature of the transmission and I have read it
> displays
> both dominance and recessive qualities.>>

And SAS is even worse, because you are presented with the possibility of
drop-dead young dogs. In dogs with the severe form of SAS, I have read
that there is a 75 percent likelihood of death by age 3!!!

The mode of inheritance of SAS in Pyrs is unknown. In Newfs, the breed
most often used as a "model," the inheritance mode is dominant with
variable penetrance. Under a dominant mode scenario, this means that
there are no carriers, per se, but only affected and unaffected.
Therefore only one parent needs to have the disease for it to be passed
on. The problem with this is that SAS can also present almost
subclinically and may not be easily detected. In fact, you may not even
be able to definitively tell if a dog has it without a necropsy. And
then you get into the variable business, and you can see that it is a
very tricky disease that will be VERY difficult to get a handle on if it
becomes established in the breed.

Hence the recommendation from the Newf club that we act very
aggressively against it. In my opinion, the littermates, offspring, and
parents of an SAS dog should NOT be bred. Breeders will make their own
decisions, of course, but this disease is THAT serious, in my opinion.

Another researcher, in Bouviers, thinks that in that breed SAS may be a
recessive. Although the Newf model may be more likely for Pyrs, I don't
think we can absolutely assume that it is the correct one.


Darrell Goolsbee
Fort Worth, TX