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Addison in Poodles
Addison in Swedish
Added 15. January 2008
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 breed.
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
example:
Ge_
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 risks:
- 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 bred.
- 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
Registry, www.poodlehealthregRegistry,
Health issues and test results, good and bad, are also included in the PHR's
online database at www.phrdatabase.online database at
www.phrdatabase.<WBR>org .
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 purposes.
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
_ngtessier@gmail.ngt_ (mailto:ngtessier@gmail.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, go to:
*Summary: *
- 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
(http://cgap.ucdavis.edu/ST%20kit%20request.htm) for more information,
or email _ngtessier@gmail.ngt_ (mailto:ngtessier@gmail.com) .
- Breeders should proceed with the assumption that Addison's is a
polygenic disease.
- 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 www.poodlehealthregPoodle Hea
Much thanks goes to the Poodle community in anticipation of your generous
support!
Natalie Green Tessier
Heritability and complex segregation analysis of hypoadrenocorticism in the standard poodle
Author(s)
FAMULA T. R. ; BELANGER J. M. ; OBERBAUER A. M.
Résumé / Abstract
The heritability of hypoadrenocorticism (Addison's disease) was evaluated In 778 standard poodles with known Addisonian phenotypes. Addisonian status was confirmed clinically by adrenocorticotropic hormone (ACTH) challenge and 8.6 per cent of the poodles enrolled in the study were classified as being Addisonian. Hypoadrenocorticism affected both sexes with equal probability (P>0.1). The most common coat colours had a negligible effect on the incidence of hypoadrenocorticism (P>0.09), although red coat colour had a significant Impact on the disease, probably due to the relatively small numbers of dogs with that coat colour. The heritability of hypoadrenocorticism in the standard poodle was estimated to be 0.75. Complex segregation analyses suggested that hypoadrenocorticism In the breed Is influenced by an autosomal recessive locus. Clarification of both the heritability and mode of inheritance of hypoadrenocorticism in the standard poodle allows for better-informed breeding decisions.
Department of Animal Science, University of California, Davis 95616, USA.
Hypoadrenocorticism in a
family of Standard poodles.
Shaker E,
Hurvitz AI,
Peterson ME.
Department of Medicine, Animal Medical Center, New York, NY 10021.
Thirty-one ancestors of a Standard Poodle with hypoadrenocorticism
were located. Hypoadrenocorticism had been confirmed in 8 of 32 dogs
(25%) by use of ACTH response testing or necropsy. In 2 additional
dogs, hypoadrenocorticism was diagnosed on the basis of
characteristic clinical signs and serum electrolyte abnormalities
consistent with adrenocortical insufficiency. Although an obvious
pattern of inheritance was not evident, the high prevalence of
hypoadrenocorticism suggested that heredity may have been a factor
in the development of idiopathic adrenal insufficiency in dogs of
this family.
source:
http://www.ncbi.nlm.nih.gov
Muscle Cramps in Two Standard Poodles With Hypoadrenocorticism
From the Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, 4700 Hillsborough Street, Raleigh, North Carolina 27606.
Address all correspondence to Dr. Olby.
Two standard poodles were evaluated for painful, episodic muscle cramps affecting their thoracic and pelvic limbs. Both dogs had been diagnosed with hypoadrenocorticism and were being treated with fludrocortisone acetate and prednisone when evaluated for muscle cramps. However, the muscle cramping started approximately 1 month prior to the diagnosis of hypoadrenocorticism. Findings on general physical examination included lethargy and dehydration. Neurological examination was normal between episodes. Serum biochemical abnormalities included hyperalbuminemia, azotemia, hyponatremia, hypochloremia, and hyperkalemia. Altering treatment to desoxycorticosterone pivalate resolved the electrolyte abnormalities and the episodes of muscle cramping in both dogs. The authors conclude that hypoadrenocorticism can be associated with episodes of painful muscle cramping in standard poodles.
Addison's Disease in Poodles
This information is not meant to be a substitute for veterinary care. Always follow the instructions provided by your veterinarian.
Addison’s disease occurs more
commonly in female dogs Addison’s disease (hypoadrenocorticism) is
caused by a lower than normal production of hormones, such as cortisol,
by the adrenal glands. The adrenals are small glands that are located
near the kidneys. Adrenal hormones are necessary to control salt, sugar
and water balance in the body.
Addison’s disease occurs less commonly than the opposite condition, Cushing’s disease (overproduction of cortisol) in dogs, and is rare in cats.
Addison’s disease occurs most commonly in young to middle-aged female
dogs. The average age is about 4 years old.
Signs of Addison’s disease may
appear suddenly, or be intermittent The signs of Addison’s disease
may be severe and appear suddenly, or may occur intermittently and vary
in severity. Signs may include weakness, depression, lack of appetite,
vomiting, diarrhea, and occasionally increased thirst (polydipsia) and
increased urine production (polyuria).
When a pet is stressed, their adrenal glands produce more cortisol, which helps them deal with the stress. Because dogs with Addison’s disease cannot make enough cortisol, they cannot deal with stress, so the signs may occur or worsen when stressed. What a dog finds stressful depends upon his/her temperament. For many dogs, any change in their day-to-day routine, such as being boarded or having house guests, is stressful and may precipitate or worsen signs of Addison’s disease.
On
examination of dogs with Addison’s disease one may see depression,
weakness, dehydration, weak pulses and sometimes a slow, irregular heart
rate.
Dogs with Addison's disease
cannot cope with stress Routine laboratory tests often show a low
blood sodium and high blood potassium. Loss of water, in vomit and
diarrhea, can lead to dehydration. Severe dehydration increases waste
products in the blood (creatinine and blood urea nitrogen = BUN) that
are normally eliminated by the kidneys. Addison’s disease can be
confused with primary kidney disease. Some dogs with Addison’s disease
have low blood sugar. See What Do Those Lab Tests Mean? for additional
information about laboratory tests.
Sick dogs often show a pattern of changes in their white blood cells (WBCs) called a stress leukogram. This pattern of changes in the WBCs is caused by cortisol. The absence of a stress leukogram in a sick dog may be a clue to consider Addison’s disease. The urine is often dilute.
Increased blood potassium can cause life-threatening abnormalities in the heart rhythm. These abnormalities can cause the heart rate to be slow and irregular and can be seen on an electrocardiogram (ECG).
X-rays of dogs with Addison’s disease do not show any specific abnormalities. The heart may appear smaller than normal and rarely the esophagus (tube from mouth to stomach) can be enlarged.
The
history, physical examination, and initial laboratory tests provide
suspicion for Addison’s disease, but a more specific test, an ACTH
challenge, should be performed to confirm the disease .
Long-term treatment can be given
by mouth or as a shot There are two stages of treatment for Addison’s
disease; in-hospital treatment and long term treatment. Very sick dogs
with Addison’s disease require intravenous fluids, cortisol-like drugs
and drugs to neutralize the effects of potassium on the heart.
Long-term treatment involves the administration of hormones in one of two forms; either a daily pill or a shot that is given about every 25 days. Because dogs with Addison’s disease cannot produce more cortisol in response to stress, stress should be minimized whenever possible. It may be necessary to increase the amount of hormones given during periods of stress (e.g. boarding, surgery, travel, etc.).
With
appropriate treatment for Addison’s disease, dogs can live a long and
happy life.
Washington State University
assumes no liability for injury to you or your pet incurred by following
these descriptions or procedures.
Source:
http://www.vetmed.wsu.edu/Cliented/addisons.asp