Addison's disease is a rare hormonal disorder of the adrenal glands. It has been diagnosed in both European and American Leonbergers. It is serious and can lead to death if undiagnosed. However, if diagnosed correctly, it can be very successfully managed with medication. Affected dogs often have periodic vomiting and diarrhea, lethargy, exercise intolerance, and weight loss.
Symptoms come on gradually and become worse with time.
It is typically a disease of young to middle-aged female dogs. It can be definitively diagnosed with blood tests. The bloodlines that have shown evidence of Addison's disease are being carefully monitored in the United States by the LCA's Heath Committee. These can be corrected with a relatively minor surgical procedure. This condition is considered a major fault, however, and dogs known to carry the gene are not allowed to breed.