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Addison's Disease (Hypoadrenocorticism) in the Dog

What is Addison's Disease?

Addison's disease can affect both humans and dogs, It is rare in cats. Another name for this is hypoadrenocorticism. Most commonly the adrenal glands are destroyed by the patient's own immune system. In normal body function these glands produce the steroids call cortisol (glucocorticoid)  and aldosterone. Diseased glands cannot produce adequate levels of these hormones and normal body homeostasis is disrupted. Low cortisol levels reduce the body's ability to respond to stress and also reduce the level of sugar in the blood (sugar is a major source of energy for the body). Low levels of aldosterone create an imbalance of the electrolytes sodium and potassium, leading to nerve and muscle dysfunction. Dogs with Addison's disease can experience a life threatening crisis, resulting in collapse, abnormal heartbeats or death due to no heartbeat at all.

Predisposing Factors

Most dogs affected with Addison's disease are young to middle aged, most dogs being under 7 years of age. It is more common in females than males. Certain breeds are more prone to be affected by hypoadrenocorticism. These include: West Highland White Terrier, soft-coated Wheaten Terrier, Cairn Terrier, Rottweiler, Great Dane, Bearded Collie, Portuguese water dog, Labrador Retriever, Leonberger, Great Pyrenees, Pomeranian, American Cocker Spaniel, English Springer Spaniel, Standard Poodle, and Nova Scotia Duck Tolling Retriever.


It is easy to confuse Addison's Disease with other illnesses because the signs can be intermittent and non specific, such as: lethargy, vomiting, diarrhea, weakness, and loss of appetite. Other signs can also be present:

  • Dehydration
  • Polyuria (increased urination) and or polydipsia (increased thirst)
  • Weakness, shaking or trembling
  • Bloody stool
  • weak femoral pulse
  • Shock
  • Slow or irregular heartbeat
  • Collapse
  • Abdominal pain

As mentioned earlier a dog experiencing an Addisonian crisis can be at risk of death, and requires emergency intervention with hospitalization, intravenous fluid therapy, normalization of blood sugar, and other supportive care.

Addison's can present in an Atypical form, where there is only low cortisol levels and no electrolyte imbalance.

Diagnosing Hypoadrenocorticism

Baseline complete blood count, blood chemistry with electrolytes, urinalysis are essential in diagnosing this disease, but a specific test called ACTH (adrenocorticotropic hormone) stimulation test is the gold standard. It measures the ability of the adrenal glands to produce cortisol before and after stimulation. Low levels of cortisol present even after stimulation are diagnostic of Addison's for confirming the disease. High levels of blood potassium and low sodium also raise the suspicion that Addison's is present. Other test may also be helpful, depending on the clinical symptoms present.


Once the adrenal glands are damaged they cannot recover, so the dog must be on lifetime replacement hormone therapy;  usually daily prednisone to replace cortisol, with or without an aldosterone replacement medication. There are two options for aldosterone replacement. The first is an oral medication called Florinef (Fludrocortinef), and is given daily. Alternatively there is a monthly injection of desoxycortisosterone (DOCA).

Regular checkups with your veterinarian are crucial to stabilizing and maintaining a dog with Addison's. When a potentially stressful event is anticipated this dog's may require adjustment in their medication to tide them through.  

At DR 4 PETS we care about your pet's quality of life and want you to be informed of conditions that impact that quality. We understand there will come a time when despite proper care and intervention the end of life has arrived. We want to be there to help you through this difficult time. We offer compassionate in-home pet euthanasia and service these areas in southern California: Ventura County (Ventura, Camarillo, Santa Paula, Ojai, Thousand Oaks, Moorpark, Simi Valley, Westlake Village), San Fernando Valley (Porter Ranch, Chatsworth, West Hills, Woodland Hills, Agoura, Calabasas).