To all Standard Poodle owners and breeders:
DNA samples are needed for a groundbreaking, well-funded, international study
that has already made significant progress toward finding the genes that cause
Addison's Disease in Standard Poodles.
Based in Sweden, this research is a collaboration between Dr. Kerstin
Lindblad-Toh of MIT's Broad Institute - currently a guest professor at the
University of Uppsala, Sweden - Dr. Åke Hedhammar of the
Swedish University of Agricultural Science in Uppsala, and Dr. Anita
Oberbauer of UC Davis.
Though not yet definitive, these researchers say their DNA microarray data
thus far suggests a complex trait with multiple loci, or gene regions,
indicated for the disease. This is consistent in both Swedish and American
Poodles. They believe that the data support a complexly inherited trait and
that breeders should use that knowledge when making breeding decisions.
This means that the disease is almost certainly a polygenic trait (controlled
by more than one gene) though they do not yet know how the genes interact. It
is most likely not an autosomal recessive as previously thought, although it
is definitively an inherited disease. Environmental contribution to the
disease is as yet unknown, but the disease is not random; it is genetic.
Additionally, there is ongoing research at the University of Utah's Lark Lab
on Addison's in Portuguese Water Dogs. Dr. Gordon Lark and his colleagues
found definitively that multiple genes are involved for Addison's in that
breed. They have now been comparing the DNA of Nova Scotia Duck Tolling
Retrievers and, most recently, the DNA of Standard Poodles, to that of PWDs to
see if the suspect gene regions are similar.
Dr. Kevin Chase of the Lark Lab analyzed exhaustive health and pedigree data
from the Poodle Health Registry and other private sources. He reportedly found
Addison's to be much less frequent in Standard Poodles than earlier studies
have shown and far less frequent than in PWDs. This means that with careful
selection, it is possible to reduce the frequency of Addison's Disease in our
While in recent years protocol called for spaying and neutering producers and
offspring of Addisonians, researchers from both the Swedish study and the Lark
Lab say this is not recommended. It is also best, Dr. Lark says, to breed
high risk dogs to very unrelated dogs to improve the chances of breaking up
the set of genes that cause the disease.
The scientists from both the Swedish team and the Lark Lab explicitly advise
that breeders proceed on the assumption that this is a polygenic trait.
Earlier methods of assessing risk are therefore no longer applicable.
Dr. Lark says that breeders can do more damage to the gene pool by the
wholesale removal of producers or offspring of Addisonians from that gene pool
than they will by very selectively breeding them. As with any serious
polygenic disease, however, it is extremely important to breed with care and
with as much knowledge of the lines as possible.
Dr. Jerold Bell writes about polygenic disease in the following article,
entitled Managing Polygenic Disease, and he uses hip dysplasia as an
Applying Dr Bell's breeding advice to Addison's Disease, breeders can follow
the same strategy they employ to avoid hip dysplasia and thereby improve their
- Affected dogs should not be bred.
- A dog with close and/or multiple Addisonian relatives should not be bred
to another with similar risks.
- Only very high quality dogs with close Addisonian relatives should be
- High risk dogs should be bred sparingly and only to those with very few
Addisonians in their lines.
- Producers and offspring of Addisonians should be replaced with a lower
risk offspring or parents of the same quality.
- In addition to numbers of related Addisonians, breeders should consider
each affected dog's age of onset, severity of onset and any extreme
environmental exposure to determine different levels of risk when assessing
depth and breadth of pedigree.
In order for breeders to make the safest breeding choices possible, ALL
Addison's Disease must be publicly reported. For Standard Poodles, the best
and most reliable method of tracking most health issues is the Poodle Health
Health issues and test results, good and bad, are also included in the PHR's
online database at
www.phrdatabase.org . There,
breeders can research the pedigrees of their own dogs and prospective mates in
order to make the most informed decisions possible. Pet owners can review
pedigrees when deciding to adopt puppies.
Blood and serum samples from Standard Poodles are requested by both UC Davis
and the Lark Lab. These are necessary for new technology, which offers a more
efficient and accurate way to analyze DNA than ever before. Samples from any
Addison's affected dogs are requested, as well as from dogs that are most
likely unaffected, which means healthy, older dogs. Any healthy dog 8 years
old and over is a good candidate, preferably those with no parent, offspring
or sibling with Addison's. This requires a visit to the vet, but the process
is very simple and brief for those who worry about their dogs' reaction to
stress. Many veterinarians will do this for free when it is for research
Additionally, adrenal gland tissue samples from both affected and older
healthy Standard Poodles are also needed by UC Davis. They will use these to
compare the DNA findings with the actual expression of genes so they can
better understand how the disease progresses and how the different loci may
interact to yield the disease. If in the near future your poodle is euthanized
and you would like his or her tissue to help this crucial cause, you can
discuss this with your veterinarian prior to such an occurrence. The vet can
then put a note in your dog's file with instructions so that it won't be
necessary to discuss at a more emotional time.
To send a Standard Poodle sample to the Lark Lab, you can contact me at
email@example.com. Any samples
sent to the Lark Lab will also be sent to UC Davis after they are compared to
PWD samples. To send samples directly to UC Davis, and for more information,
- A recent, significant study on Addison's Disease has data that supports
a complexly inherited trait, not an autosomal recessive mode of inheritance.
- DNA and tissue samples from Addisonians and older healthy dogs are
urgently needed to complete this research. Go to
for more information, or email
- Breeders should proceed with the assumption that Addison's is a
- Breed high risk dogs to highly unrelated dogs with lower risk.
- Do not remove producers or offspring of Addisonians from the gene pool;
instead, replace them with high quality offspring or parent with lower risk.
- Assess both the status of direct ancestors as well as all lateral
relatives when considering a breeding.
- Note ages of onset, severity of onset, and environmental conditions and
events for every individual Addisonian.
- Publicly report all cases of Addison's Disease, preferably to the Poodle
Health Registry at
Much thanks goes to the Poodle community in anticipation of your generous
Natalie Green Tessier
Poodles de Grenier