Addison’s Disease in PWDs

Understanding the Genetics of Addison’s Disease in PWDs

April 18, 2021 07:00 ET — The Portuguese Water Dog Foundation is excited to kick off a new research study to investigate the genetics of Addison’s disease — specifically in PWDs! The study will be conducted by Drs. Steven Friedenberg and Leigh Anne Clark and their research team at the University of Minnesota College of Veterinary Medicine and Clemson University.

The project will use a state-of-the-art approach to mapping complex genetic traits. Their ultimate goal is to understand the genetic risk factors for Addison’s disease in PWDs and to develop a test that can help breeders decrease the incidence of the disease. The Foundation has committed to donating more than $225,000 during the three-year study.

As many of you know, Addison’s disease is a common inherited problem in PWDs. The disease, also referred to as primary hypoadrenocorticism, is an immune-mediated disorder in which the body attacks the outer layer of the adrenal glands. This leads to a lack of key hormones that regulate the stress response and water/electrolyte balance. PWDs with Addison’s often present with waxing and waning gastrointestinal signs, a finicky appetite, or weakness. In some cases, dogs present to veterinarians with life-threatening problems that can be fatal if not recognized and treated promptly. Therapy for Addison’s disease is available but requires lifelong commitment by owners with hormone replacement therapy.

Recruiting PWDs

The study will begin May 1, 2021. The research team is actively seeking PWDs in the US and Canada of any age who have Addison’s disease, as well as PWDs over 10 years of age without Addison’s disease. All that’s required is a small blood sample. The study will pay for all costs, including shipping to the lab.

For additional information, please visit the study website at or email the research team directly at

Registration is Open!

2nd Study: 10-minute Survey

In addition to this important study, Dr. Friedenberg is also conducting a second study that he would like to open to all PWD owners in the US and Canada. This second study aims to understand the environmental exposures that trigger Addison’s disease. Owners of heathy and affected dogs of any age can participate.

All that’s required for the second study is a 10-minute survey that you can complete from your computer or mobile device. You can access the survey through this link Please email if you have any questions about the survey.

The Foundation looks forward to providing you with updates as we move forward with this important genetics research!

Additional Resources

Detailed study description
FAQs about Addison’s Disease in PWDs

Published Research

A case-control survey study of environmental risk factors for primary hypoadrenocorticism in dogs.

Authors: Amy E. Treeful, Kelly M. Searle, Dana M. Carroll, Kathleen J. Yost, Anna L. Hedger, Steven G. Friedenberg

Published: 13 October 2023, Journal of Veterinary Internal Medicine


Dr. Friedenberg’s on March 28, 2023 on Addison’s disease and his investigation into the genetic component of the disease. This research made possible through your generous support of the Portuguese Water Dog Foundation.

Your continued support is needed to further advance Addison’s disease research in Portuguese Water Dogs. 

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