
Barbara J. Andrews, TheDogPlace.org Publisher
In the mid-80's,
novice dog breeders rushed to test for VWD (von Willibrand's Disease) while accusing everyone else’s dog of having it.
In 2016 there are virtually no statistics on
incidence of canine von Willibrand's Disease - just a lot of hype
about testing.
A
little first-hand background. VWD was said (by a nobody breeder who had
"clear" dogs) to be rampant in Akitas. My veterinarian, Joel Jensen, said he would test my dogs
(Akitas) if I wanted to waste the money but having
cared for them for four generations, he figured we’d know if I had a bleeder.
“What about a
VWD carrier?” I asked. “What
about it?” said he. “If you breed a carrier to a clear you might get a carrier.
Might not. Since you don’t go out for stud service, the odds of you getting
any bleeding disorder are
about zilch. But I’ll test if you want…..” Made sense to me so I skipped
the test. As of this 2016 update, no dog of my breeding has ever had or ever produced VWD.
Insight on breeder eyesight - with all the
to-do about CHD, VWD, etc. why do breeders not see wobbly hindquarters, popping hocks, sagging toplines, pounding fronts, and faulty temperaments unless they
are in someone else's kennel?
20 years later... Toy Fox Terrier
breeders became excited about DNA testing for congenital hypothyroidism with goiter
(ref #1). Curious about how
the CHG test came to be developed for a rare condition in a
rare breed, I contacted
breeders and Dr. Fyfe
* ref 1 for statistical data. The response was
convincing. Of 32 responses, there were two people who "knew of a CHG affected litter" but only
one person reported having experienced CHG. Two others admitted that upon genetic testing
they discovered they had a carrier. Why was the test even developed?
($$$) This we
know. CHG affected dogs can’t spread the gene because they DIE as
infants. The
puppy will strangle as the goiter grows. Nature immediately
weeds out that unhealthy gene package just as it does other serious
congenital defects unless breeders intercede to prolong life.
In the 60's breeders were convinced that CHD (canine hip dysplasia),
was a simple recessive defect. Everyone rushed to their veterinarian for
OFA (Orthopedic Foundation for Animals)
X-rays. Vets rejoiced at the extra income and breeders groaned at the
expense and agonized over the anesthesia risk. Then a veterinary friend
did a little research and I began to expose the profitable practice that added
very little to the canine gene bank but lot of $$$ to the OFA bank. The
problem?
1.) OFA x-rays failed to reduce the overall percentage of
canine hip dysplasia despite judicious genetic pairings.
2.) Readings were
inconclusive and often changed when challenged, re-xrayed or re-submitted.
I repeatedly and
publicly challenged Dr. Corley in
various magazine columns as to why OFA only certified
two joints out of at least ten major joints which affect soundness?
Other columnists, breeders, and veterinarians picked up on the subject. Finally,
after years of badgering, OFA began to certify elbows.
But there was
still a major flaw in the OFA system, one that affected thousands of
breeders who strived to make intelligent breeding decisions based on
reliable genetic data. I continued to challenge Dr. Corley on why OFA refused to
require
positive I.D. such as tattoo, and later, microchip. As of 2006 when this
was first published, OFA still did not
require positive identification of the dog being X-rayed. I exposed the
horrible truth about "Glow In The Dark Dogs"
* ref 2
with good hips that were repeatedly
substituted for questionable or failed dogs. Finally, after many years of
badgering and bad press, OFA, CERF, and now, CHF require some sort of positive identification.
Was There Dishonesty In Deposits To The
Gene Bank?
We had been allowed to believe that expending all that time, $$$, and effort was
going to prevent something. Astute breeders wrote or called, saying
they had been misled and thanking me for pointing out that almost all health
testing, from Xray to CERF is diagnostic, not
predictive. It's like being tested for diabetes or heart disease.
An OFA number only means only that the dog x-rayed normal at that time. It
does not mean he won't develop
CHD and certainly is no guarantee that he won't produce it. So an OFA number is only good for current bragging rights
because, c'mon, let's be honest, how many dogs have you re-certified?
If top winning, great-moving dogs can fail to pass OFA while dogs with obviously bad rear
movement sport OFA numbers, what does it all mean? Genetic tests are
supposed to clear up any confusion and worry, right?
Breeders might want to
re-think the risk of anesthesia just to get a piece of paper that may only be good
for a few months.
Exactly the
same is true of eye exams. The standard of certification is called CERF, Canine Eye Registry Foundation. It is a risk-free test, often
available at dog shows BUT - it too is only diagnostic. CERF certification does not mean that the dog won't develop a serious
problem such as lens luxation which is what happened to my English import Mini-Bull terrier only two weeks after she was CERF certified! The
real tragedy in that is that I learned it was not that unusual for a CERF-certified dog to literally "go blind."
Most such tests are not predictive and stupidly, I was prepared to breed the
bitch.
The same can
be said of color doppler heart exams. I know from personal experience and heartbreak.
They cannot predict and they can not reveal genetic factors. Like most
health testing, dopplers are a useful diagnostic tool.
You can stop
reading right here if you don't like where this is going. Such tests are
important, useful tools. Every breeder should carry a good tool kit but
it isn't the saw and hammer that builds a house, it is the carpenter who knows
how to use the tools!
Breeding good
dogs is not rocket science. Regardless of the health defect, you would never breed from or to an affected dog.
An affected dog would not be winning in the show ring. Putting a dog on
public display to be examined by a judge might, in
itself, be a pretty good exclusionary test for cataracts, primary lens luxation, orthopedic problems including hip and elbow dysplasia, spine, and
neck abnormalities, and in fact, the level of exertion required for some dogs to
get around the show ring clearly expose heart or airway problems!
Perhaps there's a better predictive way to be sure you are breeding to and
from healthy dogs. With the advances in DNA testing, you may be
able to ascertain whether a non-affected dog is a carrier for a growing list of health defects.
A DNA swab is non-invasive, unlike x-ray and anesthesia. It will take some
time to see how reliable DNA tests are for VWD, CERF, CHG, etc. but they will be
your best tool.
For example. your DNA-cleared dog can only produce affected pups if bred to an affected dog. No way will you
knowingly do that! If the DNA cleared dog produces a carrier, that means the other
dog is a carrier. Can two clear dogs produce a carrier? Can a clear dog develop the problem?
We're told that in primary lens luxation (PLL) that's possible but the new DNA
testing looks like the best breeder tool.
If If you plan to advertise
a dog at stud, in today's market you better have him genetically cleared for every potential
defect known to that breed! Even so, your competitors will still whisper and
insinuate things about your stud's genes. If your dog turns out to be a carrier,
you only breed to cleared dogs. No big deal. It is not the end of a breeding career. Your Doberman might carry
blue or fawn but if you don't want that in your line, you don't breed to a dog
that carries it.
Novice breeders are quick to throw stones at proven (tested) breeders who are
slow to jump on every bandwagon. Such breeders know their bloodline, including
what dark genes lurk there. They also know that “kennel blindness” occurs on
both sides of the lenses.
I
have written many times "You
can live with and love an unsound or sickly dog but a dog with bad temperament
is a joy to no one." It became a popular quote for a very good reason
- it's true. Isn't breed temperament and character far more important than
proving your dog has good hips, eyes, or heart?
So how are you going to prove
your dog's personality is correct
for his breed? Show him! Take your dog out where other breeders can
admire (or reject) him and have him "tested" by people who are paid to assess
both physical and mental soundness appropriate to the breed. AKC dog show
judges are pretty darned good at what they do. Exhibiting your dog
(without drugs!) is a great temperament test. A dog with a sound
temperament typical and proper for his breed will produce the most important
element of owning a dog - good personality typical of the breed and mental
acuity and stability.
Puppy buyers
have been schooled to ask for health certifications but they don't realize that the sire or dam has to be locked away when visitors
come, or that it can't breathe or reproduce naturally! AKC must have read
this over a decade ago because today the American Kennel Club offers Canine Good Citizen tests
in addition to structured Obedience and Agility, both of which test a dog's I.Q. and stability.
There is one
reality we must face before we get all wound up about the latest, newest, desperately needed DNA test or health
screening. In spite of all that we do, genetic problems are
increasing. Every year new diseases are diagnosed in companion animals.
It isn't that researchers and vets are getting better at what they do. It
is a sign of the times and equally true in the human population. Just
thought I'd mention it...
So even with
all the tests, are breeders able to fix canine eye, heart, organic,
reproductive, and orthopedic defects? We haven't made much progress
in some breeds with problems we can SEE. A casual look around any show ring
clearly reveals some breeders would rather paint their gene bank with paper
certificates than with good structure, health, and temperament. If you
doubt this, see Health Defects in Purebred Dogs (3) study the then and now
photos and don't be discouraged, be inspired to do better and work harder in
your breed club.
Maybe the answer lies in human nature. If we can buy
bragging rights for a hundred bucks, that is enough for some breeders. My repeatedly (and ignored) suggestion is that all breeding dogs should earn a
champion, field, obedience, or agility title before they are bred regardless of how clean the
genes are!
Genetic testing is a
useful tool. Think of it as one of many brushes in the artist’s case. Do we teach breeders to step back and view the landscape before
splashing color on the canvas? Or do we encourage them to paint with just one
color, knowing that our canvas will easily win over theirs?
I don’t have a lot of letters after my
name. I just have a lot of top ranked winners and producers. I’ve been creating juried (judged) works of art and like many
others who learned the hard way, I did it before we had such wonderful tests and
tools. We learned “genetics” before words like polygenic, homozygous, and
DNA were invented! We will gratefully use what science has afforded us but the
test has yet to be invented that will replace logic, attention to detail, pedigree research and
hard work!
If we have truly learned
anything about genetics while painting our gene bank, it is how to create a masterpiece that can be reliably reproduced. That is the challenge.
(#1) DNA
testing for congenital hypothyroidism with goiter -
(# 2)
X-ray Radiation Risks -
(# 3)
Health Defects in Purebred Dogs
Portions excerpted from ShowSight Magazine columns, circa 2006
TheDogPlace.org EST 1998 © 062163
https://www.thedogplace.org/Genetics/painting-the-gene-bank_Andrews062.asp
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