Addison’s Disease

Poorly functioning adrenal glands produce low amounts of the body’s cortisol. Learn the signs of this disease. Also know how to recognize trouble with medication dosages.



My 5 year old mixed breed dog was diagnosed with Addison’s disease last August. He is currently on 5 mg. Prednisone and 5 mg. Florinef daily. Since he started these medications he has been experiencing excessive urination, mostly when he is asleep. Is there something I can do to control this? I have several other pets so reducing his water intake would be difficult. Any suggestions you might have would be greatly appreciated.


Dr. Nichol:

I’m glad you wrote in with this question. Excessive drinking and urination is not only an important physical sign but can be downright tough on your floors.


For the uninitiated, I will start with an explanation of Addison’s disease. This is a condition of the hormone producing glands that sit on either side of the abdomen just in front of (or in the case of humans just above) the kidneys. In addition to producing the hormone adrenaline, the adrenals turn out cortisol (the body’s own form of cortisone) plus aldosterone. The functions of cortisol and aldosterone are many and they are essential to normal physical function. But most important, a dog with untreated Addison’s disease will tend to be lethargic, eat poorly, and may occasionally vomit and have diarrhea or constipation. Since these are pretty vague symptoms, Addison’s disease can be easily mistaken for other problems. I salute your veterinarian for making a difficult diagnosis.


Because Addison’s disease is really an underperformance of a hormone producing gland, replacing those hormones in your dog’s body is the treatment of choice. Hence the deficiency of cortisol is replaced by the drug prednisone while Florinef is used in the place of the deficient aldosterone. The only question remaining then is dosage. Since bigger dogs need more, these replacement hormones are usually dosed according to weight. While you did not include your dog’s weight in your letter, I will assume that an overdosage of prednisone is responsible for his excessive drinking and urinating.


What should the dosages really be? My recommendation is that you connect with your veterinarian and report the problem. The best course might be to repeat the tests used for diagnosis of Addison’s disease-the ACTH stimulation test plus serum electrolytes. These tests will confirm whether your dog still needs these medications in the first place. Secondly, it will help the doctor know how severe the deficiencies are that need to be corrected. But the last test is the one that may be more useful than the others: How is your dog feeling and what are your observations at home? Any dog who produces so much urine that he is losing control while he sleeps definitely needs an adjustment in his dosage.


Lastly, and most important, if you have a pet who drinks a lot of water, DO NOT restrict his intake. Excessive thirst is a sign of a truly critical physical need. Water deprivation can only lead to dehydration and possible death. Pets who drink a lot of water need a lot of water. They also need a doctor.






My Westie has been diagnosed with Addison’s Disease.  He gets injections every 3 weeks and prednisone daily. What can I expect in future?


Dr. Nichol:
Addison’s disease (low hormone output from the adrenal glands) is more common in female dogs of several breeds, West Highland white terriers among them. Affected dogs are prone to lethargy, vomiting, gradual weight loss, poor appetite, and sometimes diarrhea. Some tremble and drink or urinate excessively. Symptoms may come and go.


Fortunately, the diagnosis is straight-forward in most cases, using blood tests. There are a few treatment options (including injectable and oral medications) to correct hormone deficiencies and electrolyte imbalances. Many Addisonian dogs respond well and do fine into old age. Those who get careful monitoring by their doctors have the best long term results.