2017 March April

Q&A
Do These Genes Fit?
Isn’t it true that if you are trying to
determine how much risk a has for
something and there is information
missing, the risks are skewed toward a
more positive outlook? There’s no way you
can possibly get all the health info for a
pedigree, so what’s the point?
It’s true no one will ever have 100-
percent knowledge – not just of this, but of
anything as complex as genetics. However,
the more breeders know about where risks
lie, the better they can avoid risky matings.
This is why it is imperative that people be
open about genetic issues. But even if
breeders are totally compliant in reporting,
there will still be unknowns because not
every puppy out of every litter will be of
known status. Some die before they would
have developed a disease, some puppybuyers
may never tell the breeder that
something went wrong, and some dogs you
simply lose track of because people move
or relinquish the dog and don’t tell you.
Certainly the best thing is for everybody
to open up. Mark information submitted to
OFA “open” and send health info and test
results to ASHGI’s IDASH Open Health
Database. In Europe reporting and open
publication of a number of health-screening
results is common, if not required. The
French even have a voluntary open epilepsy
registry. I doubt we will ever see mandatory
reporting of anything in the U.S., but the
responsible thing to do is share this
information – especially on things that
typically aren’t included in registries.
We can reduce the incidence of
diseases considerably if we provide
everything we can to health databases and
freely exchange health information with
peers the same way we share information
on working or show traits. This should be
expected rather than exceptional behavior.
But just because this is not currently the
Send your questions to:
C.A. Sharp
1338 Trouville Ave.
Grover Beach, CA 93433
ph. 805-473-0078
e-mail: 51ca@ashgi.org
case it doesn’t mean we should declare it
hopeless. Giving up or sticking to the don’tshare
status quo makes you part of the
problem, not part of the solution. Every
responsible breeder must do the best he or
she can with the information at hand and
be open even if others are not.
Even though all data aren’t available,
there is a lot we can do to skew the odds in
our dogs’ favor. At the moment making
health screening a priority and studying
pedigrees for health risk with such
information as is available is the best
course. Meanwhile, push for openness and
encourage others to participate in open
health registries and breed health research
and use all available tools to evaluate health
risk in your dogs and potential matings.
I had a dog OFAed and the vet found
something wrong in a part of the knees.
They had a “multipartite sesamoid bone”
– 2 little round bones behind the stifle that
are normally one. The vet said this can be
a normal variant but it makes me nervous.
Is this heritable?
I think the key here is the vet saying it
can be a “normal variant.” In other words,
it’s something that happens sometimes that
generally doesn’t have any impact on
function. I did a little reading on this and
in most cases it does not cause the dog any
problem though occasionally one might see
lameness.
Rottweilers seem to have it fairly
frequently so there may be a genetic
tendency there, but in other breeds –
including collie-type breeds like the Aussie
– it is sporadic, which indicates it is
unlikely to be inherited. If something is
inherited you will see a familial pattern of
occurrence.
I’m looking at an Aussie puppy but the
male parent is a carrier for CEA. What is
the chance his offspring will have this
disease? Will it only be an issue for the
pups with light-colored eyes?
CEA (Collie Eye Anomaly) has
nothing to do with eye color; it causes
certain defects in the back of the eye. The
disease is genetically recessive, which
means a puppy has to inherit two copies of
the mutation to have the disease. If one of
the puppy’s parents is a carrier and the other
tested clear then the puppy might also be a
carrier but it cannot have two copies and
therefore cannot have CEA itself.
If the other parent is not tested then
one can’t say for sure whether the puppy
will or will not have two copies and you
may want to have it DNA tested for your
own peace of mind. Even in the worst case
scenario where the puppy is affected, it will
probably have functional vision, though
you wouldn’t want to use such a dog for
breeding. Carriers should be bred to cleartested
mates to be sure no offspring will be
affected. In rare cases the disease can be
blinding.
If the puppy’s eyes were examined by
a veterinary ophthalmologist prior to seven
weeks of age and found to be normal that
is another indication that the puppy is
healthy and cannot have more than one
copy. (After seven weeks CEA can be
difficult to diagnose with an eye exam.) All
Aussie puppies, including pet puppies,
should have an eye exam before they go to
their new homes.
AUSSIE TIMES March-April 2017 65