The Great Pretender: Hypoadrenocortism (aka Addison’s Disease)

 In Pet Talk: In the News

Hypoadrenocortism, otherwise called Addison’s Disease, occurs when the adrenal glands are not making the hormones mineralocorticoids and glucocorticoids.  Mineralocorticoids regulate electrolytes such as sodium and potassium in the body. Glucocorticoids, such as cortisol, are necessary for proper metabolism of fats, proteins, and carbohydrates.

How does Addison’s Disease occur?

Primary Addison’s Disease occurs when an animal’s immune system attacks it’s adrenal gland and destroys it. This immune system attack can be set off from many things, like cancer, trauma, or a vascular event.

Secondary Addison’s Disease occurs when the pituitary or hypothalamus are not signaling the adrenal glands to release hormones. This can be because these parts of the brain are diseased due to a congenital defect, inflammation, or cancer.

Who commonly has Addison’s Disease?

Addison’s Disease typically occurs in younger to middle-aged dogs. It is also more common in females but can occur in males.  Some breeds that are predisposed include labradors, retrievers, standard poodles, and collies.

What are warning signs of Addison’s Disease?

Clinical signs of this disease are the waxing and/or waning of vomiting, diarrhea, weight loss, lethargy, weakness, anorexia, and shaking. In an Addisonian crisis, the animal will possibly have low blood pressure, a low heart rate, dehydration, collapse, or be in shock.

How will your veterinarian test for Addison’s Disease?

  • Chemistry panel: This test shows increased kidney values, elevated potassium and low sodium, low protein levels, low cholesterol, low glucose, and high calcium.
  • CBC: This test shows a lack of stress changes which typically causes an increase in neutrophils and monocytes and a decrease in lymphocytes. A mild anemia may also be shown.
  • Baseline Cortisol: This test will be low, indicating lack of cortisol in the blood.
  • ACTH stimulation test: This test is the disease-specific test used to verify a diagnosis of Addison’s.

Why is Addison’s Disease called “The Great Pretender”? 

The changes that can be associated with Addison’s Disease can be misleading; results from the previous listed tests actually be interpreted as other diseases, as listed below.

Abnormalities of
Addison’s Disease
Other Possible Causes
Low blood glucose Toxins, sepsis, cancer, kidney failure, starvation
Elevated kidney values Dehydration, kidney failure, urinary obstruction
Electrolyte changes Kidney failure, vomiting and diarrhea, pyometra, parasites, diabetes, toxins
Low heart rate Cardiac disease, toxins, medications
Low blood pressure Dehydration, cardiac disease, shock, toxins, trauma, hemorrhage

Waxing/waning signs alone can cause confusion for both owners and veterinarians as to what could be causing the clinical signs.

How do we treat Addison Disease?

If a pet experiences an Addisonian Crisis, they will go into crisis and require emergency care. Typically, intravenous fluids, injectable steroids, GI medications, and antibiotics are used. Blood pressure medications and plasma may also be warranted in severe cases.

Pets with Addison’s Disease will require lifelong treatment with medications; these drugs will substitute the mineralocorticoids and glucocorticoids that their body is not producing. To substitute the mineralocorticoids, pets have two options: fludrocortisone, a daily, oral pill or DOCP, an injection that is required every 28 days. To substitute the glucocorticoids, oral pill, prednisone, is typically used daily.

Should I worry if my animal has Addison’s Disease?

If your animal is diagnosed with Addison’s Disease, don’t fear. The prognosis is overall good with continued treatment and close monitoring.

Kerri Wiedmeyer, DVM
WVRC ER Veterinarian

Start typing and press Enter to search

dog paws for hit by car article