Addison’s in dogs, otherwise known as hypoadrenocorticisim, is an endocrine disorder that affects dogs of all ages and breeds. It happens when the dog’s adrenal glands fail to produce enough hormones, particularly cortisol and aldosterone.
It all starts at the pituitary gland. The pituitary gland produces adrenocorticotropic hormones, or ACTH. These hormones travel through the adrenal glands, stimulating them. They are responsible for producing hormones that are needed for various bodily functions. These include:
Cortisol. Needed for regulating metabolism, stress response, and immune function.
Aldosterone. Required for regulating blood pressure, electrolyte balance, and fluid balance.
In hypoadrenocorticism, affected dogs will have trouble maintaining normal physiological functions. This can be potentially severe and life-threatening.
What Causes Addison’s Disease in Dogs?
Addison’s in dogs can be caused by primary and secondary factors. Primary factors are those that directly affect the adrenal glands, while secondary causes usually involve another part of the body being affected, which results in a domino effect on the adrenal glands.
Autoimmune Disease
The most common cause of Addison’s disease is autoimmune adrenalitis. This is when the dog’s immune system mistakenly targets and attacks the adrenal glands. As a result, the dog’s body will experience the loss of essential hormones.
Because this damage is permanent, dogs with Addison’s caused by an autoimmune response will need lifelong management and care.
Infections, Trauma, and Tumors
Canine Addison’s disease can also be caused by physical causes. Pathogens such as bacteria and fungi can progress, infecting the adrenal glands and damaging the tissues.
Additionally, blunt force trauma can directly impact the adrenal glands when dogs are hit in the abdomen. A direct hit to the head can also affect the pituitary gland, which can impair the function of the adrenal glands.
Abnormal growths can also affect the adrenal and pituitary glands. In the adrenal glands, tumors can destroy adrenal tissue, directly hindering hormone production. In the pituitary gland, tumors can disrupt the signals sent to the adrenal glands, impairing adrenal function.
Medications
Medications, such as corticosteroids, can also impair the function of the adrenal glands. They can essentially suppress the natural function of the adrenal glands, causing canine Addison’s disease.
Additionally, the medicines for Cushing’s disease in dogs, the opposite of Addison’s, can also suppress adrenal function.
What Dogs Are Prone to Addison’s Disease?
Some dogs are considered to have a greater risk of acquiring Addison’s disease. This includes:
Portuguese Water Dog
West Highland White Terriers
Is Addison’s Disease Contagious to Dogs?
No, Addison’s disease is not contagious to dogs. It’s primarily an internal condition that results from the failure of the adrenal glands. While infections can cause Addison’s, the condition itself does not transfer to another dog.
Symptoms of Addison's Disease in Dogs
The condition is often called “The Great Imitator” because it mimics other diseases through its general symptoms. However, the disease can progress to more deadly symptoms over time. Here are the common symptoms of Addison’s disease in dogs:
Lethargy or weakness. Lethargy is often the first and most persistent symptom of canine Addison’s disease. Dogs may sleep and lie down more often than normal. They may also choose to rest rather than play.
Loss of appetite. Affected dogs may not eat at all. Even when given their favorite meals and treats, they’ll have no appetite, sometimes refusing food.
Vomiting and diarrhea. Gastrointestinal symptoms such as vomiting and diarrhea can also be present. This is due to the disruption of digestive function because of the lack of adrenal hormones. In severe cases, there will be blood present.
Increased thirst and urination. Although less common, some dogs exhibit polydipsia and polyuria. You’ll often see your dog quickly finishing its water bowl and making frequent trips to pee.
Weight loss. Because of the lack of appetite, dogs will lose a significant portion of their weight. This is also due to inefficient nutrient absorption.
Muscle tremors. Muscle tremors or visible shaking often result from imbalances in potassium and sodium levels. These electrolytes are crucial for normal muscle function and nerve signals.
Irregular heart rate. An irregular heart rate can also be expected, as this can be due to circulatory problems.
Sudden collapse. In severe cases, dogs will suddenly become weak and collapse. They might be unable to stand and move.
Complications of Addison’s Disease in Dogs
The condition can progress and lead to more complications in the dog’s body, such as gastrointestinal problems, electrolyte imbalances, and cardiovascular issues. It can also lead to an Addisonian crisis, which involves severe symptoms and the need for urgent medical care.
How Do Vets Diagnose Addison’s Disease in Dogs?
Diagnosis can be difficult since the symptoms are similar to other conditions. However, there are several tests designed to detect Addison’s in dogs.
Physical Assessment
As usual, we’ll start with a physical exam to study your dog’s condition and medical history. After a brief discussion of the symptoms you observe at home, we can proceed to more tests.
Blood Tests
Initial bloodwork is the first step in identifying potential canine Addison’s disease. Through this, our vets will look for low sodium, high potassium, and low glucose levels. We’ll also check for any signs of kidney dysfunction. These can be indicators of the disease.
ACTH Stimulation Test
The ACTH stimulation test is the most definitive method for diagnosing Addison’s in dogs. It works by taking a blood sample to measure the dog’s cortisol levels. Next, a synthetic form of ACTH is injected into the dog. After an hour, another blood sample will be taken.
In healthy dogs, cortisol levels will rise significantly. But in dogs with Addison’s disease, the two samples will be similar in measurements, with little to no increase.
Other Tests
A urinalysis, electrocardiogram, and diagnostic imaging can also be used to diagnose specific causes and rule out other conditions.
Treatment for Addison’s Disease in Dogs
Canine Addison’s disease will require long-term management and care. The process will focus on lifelong hormone replacement therapy, wherein medications will be given to mimic cortisol and aldosterone.
Glucocorticoids. A common steroid used to mimic cortisol, helping manage the body’s response to stress and regulate overall metabolism. Prednisone is typically used, given daily in oral form.
Mineralocorticoids. These synthetic hormones help regulate electrolyte balance, acting as a replacement for aldosterone. Desoxycorticosterone pivalate is a common injectable type used. DOCP is usually given every 25 to 30 days, but the frequency can vary.
In an Addisonian crisis, treatment will consist of fluid therapy, electrolyte correction, immediate hormone replacement, and other supportive care methods.
Prognosis and Daily Care for Dogs With Addison’s Disease
Once properly diagnosed and treated, Addison’s in dogs becomes a highly manageable condition. With lifelong management, they can live full, healthy, and happy lives.
Once your dog has been fully stabilized, it can return to its normal activities and routines. Regular visits will be needed for the routine doses of mineralocorticoids, as well as checkups for your dog’s overall condition.
For daily care, your dog will require a balanced and high-quality diet to support its immune system and bodily functions. Avoid high-sodium and overly processed foods. If you need help, we can discuss more about your dog’s nutritional needs.
It’s also important to keep your dog in a safe and calm environment to effectively manage stress levels. Since dogs with Addison’s cannot naturally produce cortisol, any stressful or strenuous activities should be avoided. Focus on gentle exercises and enrichment activities.
“Dog health is about daily love, smart choices, and a promise to protect their well-being.”
- Dr. Soheyl Simaei
Final Thoughts
Addison’s disease doesn’t have to be the end of your dog’s life. The key to success lies in one thing: consistent care. Give your dog its daily medication, feed a balanced diet, and create a calm, comforting environment.
Most importantly, stay in close communication with us so we can continue keeping your dog happy and healthy.
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