Addison's Disease (Hypoadrenocorticism)
The adrenal glands are known to everyone; they are hormone-producing glands located adjacent to each kidney. Their hormone products are of such importance that, without them, neither human nor canine can survive. If the adrenals are damaged and not able to produce sufficient hormones, then the result is a life-threatening condition called Addison's disease. While this disease can show up spontaneously in any dog, there is also evidence that the disease is heritable in a number of breeds.
What causes the adrenals to fail? One reason is simply an autoimmune reaction; another reason is the result of a disease process. If you see the term immune-mediated destruction, that is adrenal failure due to an autoimmune reaction. A disease process would be something like cancer that attacks the adrenals as its primary site. Adrenal failures such as these are referred to as Primary Addison's.
Addison's can also occur as a result of another problem in the body. Sometimes the pituitary gland does not secrete enough of a hormone called ACTH, or sometimes the hypothalamus gland does not secrete enough of a hormone called CRF. Addison's can even occur as a result of damage from excess steroids being prescribed. Adrenal failures such as these, that are a result of another problem in the body, are referred to as Secondary Addison's. Whether primary or secondary, the disease must be treated.
The initial symptoms are frustratingly vague; a poor appetite, lethargy, occasional vomiting. Any of these symptoms are easy to overlook in their early stages, for they are the same symptoms of everything from a cold virus to worms. Addison's disease is easy to miss in its early stages. Your veterinarian may find an elevated potassium level during a routine blood test, or they may spot an abnormal ratio between potassium and sodium. In any event, specific lab tests are available once Addison's is suspected.
As with any disease, an early diagnosis provides better options than a later diagnosis. With an early diagnosis, treatment can consist of replacing the missing hormones, either as daily pills or intermittent injection. The most common treatment regimens with early diagnosis include salting the food and drugs, such as Flurinaf (fludrocortisone) or Prednisone (corticosteroids). A late stage diagnosis is more of a crisis situation and must be treated aggressively, usually with intravenous fluids (such as glucocorticoids) to correct the acid/base balances in the blood stream.
There is a recently concluded study at Michigan State University (Department of Endocrinology, Grant #2273; Dr. Markus Rikcs; report summary pending). At the 2005 GPCA National Specialty, Dr. Rics spoke regarding Addison's disease. Thirty Great Pyrenees at the National participated in specimen collection for the study at MSU. The focus of this study (refer to published abstract) was to measure telltale antibodies released by an immune reaction in which the body's own defense mechanism destroys the adrenals. Currently, an average prevalence of 0.3% has been reported for dogs. Numerous breeds including Bearded Collie, West Highland White Terrier, Standard Poodle, Portuguese Water Dog, Leonberger, Great Dane, Airedale Terrier, Basset Hound, Soft Coated Wheaton Terrier, and Rottweiller are reported to be a higher risk. This study was supported by the GPCA but not funded by the GPCA.
Although the final report summary has not been published, the following information has been made available: The Addison's project has not been able to find a genetic component to Addison's disease in Great Pyrenees at this point. There is a possibility that Addison's may be an autoimmune reaction to challenges to the immune system introduced by repeated and multiple yearly immunizations. In other words, the practice of giving annual boosters of combined vaccines may cause the immune system to deteriorate and leave the dog susceptible to autoimmune diseases, Addison's disease being one. The researcher continues to collect DNA and pedigrees from affected dogs, and plans to continue to study the problem. If you have a Great Pyrenees diagnosed with Addison's disease, please forward DNA samples and pedigree to Dr. Ricks. All information, samples, and pedigrees are treated with absolute confidentiality.
If you know of a Pyr with a confirmed diagnosis of Addison's disease we encourage you to help with any future research by donating a DNA sample to the CHIC DNA Repository. More information and instructions
GPCA Health Committee
Addison's disease has been reported as occurring in the Great Pyrenees. The results from the GPCA Health Survey: We received 416 surveys from 9/02 to 12/04. Of this number, 7 dogs were diagnosed by veterinarians with Addison's (all were from GPCA breeders). In the 1999 survey report, 5 dogs were listed with a conclusive diagnosis of Addison's disease. If you own an affected Great Pyrenees, please complete a Health Survey so we are able to determine the actual prevalence of Addison's disease in our breed.
- Leonberger Club of America 'Leo Watch'
- Encyclopedia of Canine Veterinarian Medical Information
- WSU College of Veterinary Medicine
- Susan Ellam (copyright 1998-2002)
- Abstract - MSU Completed Grant # 2273