Addison's disease

Pet Tales
by Barry B. Burtis D.V.M.


Her name was Marmaduke. It so happens her name is quite a common one for dogs of her breed. That's because in a popular newspaper comic strip, it's the name of the dog  who happens to be a Great Dane. She was a spayed female, five years old when her disease was diagnosed.


It turns out that females are more at risk than males to develop the health problem she has. Also, Great Danes are one of the breeds more likely to be affected by the disorder. Rottweilers, Portuguese water dogs, standard poodles, West Highland white terriers and wheaten terriers are the other breeds with increased relative risk to be affected. The disease also occurs in cats without any breed predilection.


It would almost seem as if Marmaduke's illness could be considered a textbook example, because she had demonstrated the classic symptoms of the disease. In fact, a review of some of the health problems she had been having in the past was one of the things that made her veterinarian suspect this particular disorder, in the first place. In the year before here diagnosis, Marmaduke had visited the animal hospital on a couple of occasions with rather vague, non-specific illnesses. On one occasion she was presented because she had lost her appetite and had vomited several times. She seemed to respond to symptomatic treatment for the problems and was soon back to her normal self. A few months later, though, her owners noticed her appetite was off again, she had some diarrhea and was just not interested in the things that usually gave her great pleasure. She had to be encouraged to go for her walk, had no interest in playing with her little Jack Russell terrier buddy who lives nearby and just wanted to sleep on her big comfy cushion in the family room. A special diet for a few days and some medicine to treat the diarrhea seemed to get things successfully back on track again. However, when she returned just over six weeks after that visit because she had lost a kilogram in weight, was again lethargic and drinking more water and urinating more frequently than normal, her veterinarian wanted to investigate more thoroughly.


Blood and urine tests gave further support to the veterinarian's suspicion. However, it took another blood test called an adrenocorticotropin hormone stimulation test to confirm that Marmaduke had hypoadrenocorticism, commonly called Addison's disease.


With all the bad press about cortisones and steroids taken as performance enhancing drugs by athletes, it may surprise some to learn that similar hormones produced in an animal's body are essential for good health. If the adrenal glands fail to produce adequate amounts of glucocorticoids and mineralocorticoids, serious illness will result. Most often clinical signs shown by affected individuals are non-specific and are seen in other more common medical disorders particularly gastrointestinal and kidney diseases. They often follow a waxing and waning course in occurrence. Occasionally animals are presented to an animal hospital in an acute Addisonian crisis. This life-threatening collapse by a patient requires an immediate intensive medical response.


Once diagnosed, Marmaduke, as a hospital out-patient, began her life-long glucocorticoid and mineralocorticoid replacement therapy. It's in tablet form and the tablet is much smaller than the long names of the hormones in it. The dose of the medicine is increased at times of stress such as travel, hospitalization or surgery. Periodically she has a blood test to monitor the control of her disease, but once it was properly stabilized and controlled Marmaduke had an excellent prognosis for a normal life. Barry Burtis is a local veterinarian. Past Pet Tales columns can be found at www.baycitiesanimalhospital.ca