A Primer On Addison’s Disease: What is Addison’s Disease in Dogs?

In dogs, the main cause of Addison’s disease is an immune process. Often, dogs develop Addison’s disease when their immune system destroys adrenal tissue.

Addison’s disease can sometimes develop as a side effect of overtreatment for Cushing’s disease. Further, Addison’s disease can result from suddenly stopping long-term steroid treatment without a gradual withdrawal period.

For example, other less common causes include:

  • trauma
  • infection
  • cancer
  • tumor or defect in the pituitary gland

Further, some breeds are genetically more vulnerable to this disease, such as:

  • Standard Poodles
  • Great Danes
  • Labrador Retrievers
A Primer On Addison's Disease: What is Addison's Disease in Dogs?


The adrenal glands are small glands that are located next to the kidneys. They produce hormones that regulate normal body functions.  These hormones include cortisol and aldosterone, which are both essential to health.

In Addison’s disease, aka hypoadrenocorticism, the adrenal glands don’t produce enough of these hormones.

What does it look like

Dogs can show a variety of different symptoms of Addison’s disease, including:

  • lethargy
  • vomiting and diarrhea
  • lack of appetite
  • shaking
  • weakness

Bouts of illness typically “wax and wane.”  

Often, people refer to Addison’s disease as the “Great Imitator..’ That is because its signs are usually vague and can mirror a variety of medical disorders. Dogs can intermittently improve with supportive treatments. However, the symptoms will return once treatment ends.

Addisonian crisis

Addisonian crisis is a life-threatening situation when the hormone levels drop below the levels that sustain function.

Dogs that suddenly start vomiting and having diarrhea and become weak, faint, and collapse may be suffering an Addisonian crisis.  

This is an emergency, and you should seek veterinary attention for your dog immediately.

Zeus showed up at the veterinary clinic after an acute episode of refusing food and severe lethargy in the above video. Because Zeus was a young, active boy, such a drastic change raised a red flag.

The veterinarian assessed his heart and checked for anemia, evidence of obstruction, or GI distress. Next, the veterinarian ran complete blood work. After ruling out all common suspects, Zeus’s diagnosis was Addison’s disease.

Diagnosing Addison’s disease in dogs

Diagnosis is based on your dog’s history, results of a physical examination, and blood and urine tests.  Additionally, more specialized blood tests confirm the diagnosis. 

The definite text to confirm Addison’s disease is the ACTH-stimulation test. It measures cortisol levels before and after injection of synthetic hormone that regulates the production of the adrenal hormones.

Further, your veterinarian might recommend X-rays or ultrasound to rule out other causes of your dog’s clinical signs.

Treating Addison’s disease in dogs

The treatment of Addison’s disease consists of oral or injectable hormonal replacement medications.

Accurate dosage is essential. Therefore, your vet will monitor your dog’s progress very carefully, especially at the beginning of treatment.  Further, follow-up blood testing is necessary to adjust medication dosages.  Your dog will need the medication for life. They may need a higher dose during periods of stress, such as traveling or boarding.

With proper treatment, your dog’s prognosis is good. First, however, you ought to learn to observe subtle warning signs that your dog’s hormones are are low.

Annie’s story

Annie was a 6-year-old Border Collie mix. Lethargic Annie arrived at an emergency vet with severe vomiting and diarrhea. Annie’s owner suspected that, while on a walk, she might have snatched a piece of bacon. Could that be what made Annie so sick? She was clearly miserable and severely dehydrated. Pancreatitis was a prime suspect.

Either way, Annie was in such bad shape that she had to stay in the hospital for intensive treatment. The veterinarian also ran blood work and took x-rays If Annie did, she could have an intestinal blockage.

Considering how unwell Annie was, her blood work was suspiciously unremarkable. The only significant abnormality was Annie’s eosinophils. Eosinophils are a type of white blood cell. Conditions that can lead to high levels of eosinophils include allergies, parasites, and … Addison’s disease.

The veterinarian recommended a preliminary test for Addison’s. The results put Addison’s at the top of the list of the potential causes of Annie’s illness. A following specialized test confirmed the diagnosis–Annie had Addison’s.

Further reading: Addison’s Disease in Dogs: “The Great Pretender.”

Related articles:
Addison’s Disease in a Chihuahua: Kermit’s Story
Canine Addison’s Disease Awareness: Valentino’s Story
Dog Addison’s Diagnosis: Gracie Lou Clough’s Story
Hannah Gets Ill: Addison’s Disease Awareness—What’s Wrong With Hannah?

Further reading:
Addison’s Disease in Dogs – Overview
Addison’s Disease in Dogs:“The Great Pretender.”

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