Like humans, dogs have a complex endocrine system that manages the hormones that control many vital functions — growth, metabolism, reproduction, etc. Unfortunately, that system doesn’t always work as it should. In the case of Addison’s disease in dogs, one component of that system — the adrenal glands — aren’t producing as much corticosteroid as they should.
Without a normal amount of that hormone in their body, your pet’s body can “overreact” to even the most minor stressor to the point that it can become fatal. We’ll discuss what may cause this dangerous medical issue, what to look out for, and what you can do if your dog is ultimately diagnosed with Addison’s disease.
What Is Addison’s Disease?
As we briefly touched on, Addison’s disease (also known as hypoadrenocorticism) is a dysfunction of one part of the endocrine system — the adrenal glands. They are both small in size and can be found right next to your dog’s kidneys.
One of the primary functions of the adrenal glands is to produce two crucial hormones — cortisol and aldosterone. Cortisol is a stress hormone best known for triggering the “flight or flight” response. Aldosterone, a mineralocorticoid, helps control the vital balance of water and salt in the kidneys (which also manages potassium levels in the body).
With Addison’s disease in dogs, the adrenal glands’ cortex (the outer part) isn’t producing enough of those all-important hormones, leading to an inability to maintain normal biological stress levels. Without the right amount of hormones in the body to help them adapt and cope with stress, even the slightest trigger has the potential to have devastating effects.
Some dogs with Addison’s don’t show symptoms of the disease until it’s a full-blown emergency. This is known as an Addisonian crisis, and it can be life-threatening. With many dogs, this severe presentation is because clinical signs of the disease don’t become evident until 90 percent of their adrenal gland tissue has been destroyed.
What Causes Addison’s in Dogs?
In many cases, the cause of Addison’s disease in dogs is unknown. What we know is that whatever its trigger may be, an autoimmune reaction leads to the body destroying its own adrenal gland tissue. Addison’s disease tends to occur most frequently in young to middle-aged dogs (usually between three and six years old) and female dogs.
There are also certain breeds that seem to be more susceptible, including:
- Bearded Collies
- Great Danes
- Labrador Retrievers
- Portuguese Water Dogs
- Standard Poodles
- West Highland White Terriers (“Westies”)
Some veterinarians believe that cancer, a pituitary tumor, infection, or trauma can also trigger the immune-mediated adrenal gland tissue destruction that leads to Addison’s disease in dogs, although this happens less commonly.
In some cases, the condition can also be a reaction to Cushing’s disease treatment, which is the opposite of Addison’s (where too much cortisol and aldosterone are produced instead of too little). The medication often prescribed to manage this overproduction may accidentally suppress those hormones, leading to Addison’s disease.
One other form of Addison’s disease in dogs is known as iatrogenic hypoadrenocorticism. In this situation, the condition is triggered by abruptly stopping long-term steroids. Luckily, this is usually temporary and not a common cause of the disease.
What Are the Symptoms of Addison’s Disease in Dogs?
Some in veterinary medicine refer to Addison’s disease as “the great imitator,” as clinical signs can be vague and very similar to many other illnesses. For this reason, the disease is rarely based on identifying symptoms alone, and diagnosis requires a physical examination and laboratory testing (including blood work) at your vet’s office.
However, that doesn’t mean that being able to recognize some of the more subtle signs of Addison’s disease isn’t essential. Knowing what is and isn’t normal for your dog may not always catch Addison’s early, but it may help reduce its severity by leading to quicker diagnosis and treatment.
With that in mind, here are a few of the more obvious symptoms of Addison’s disease in dogs to look for.
Low Energy
If your usually rambunctious dog suddenly lacks energy, it’s often a red flag. While we think of fight-or-flight as a bad thing, the hormones released when triggered give a dog at least a temporary energy boost during times of stress.
When your dog isn’t getting much (or any) of those hormones, they can also experience a lack of “get up and go” that leads to them lying around a lot more than usual. Many dogs with Addison’s can’t even be inspired to go for walks or chase a ball, especially when the condition has gotten more severe. Don’t write sudden lethargy off as just temporary depression.
Dogs with Addison’s disease may also develop an extremely low heart rate, sometimes lower than 50 beats per minute. Addison’s can also lead to lower blood pressure or hypoglycemia (low blood sugar), all factors that can negatively influence your dog’s energy level.
Upset Stomach
GI symptoms can also be a sign of Addison’s disease in dogs, especially nausea, vomiting, and diarrhea. This GI distress can often lead to muscle and weight loss, making your dog look like they are slowly wasting away.
These symptoms can also come and go, so if you’re noticing a pattern with your dog’s upset stomach issues, it’s always best to have your DVM take a look.
Increased Thirst
Although the adrenal glands are located next to the kidneys and not part of them, one of the hormones they secrete is crucial for preventing fluid and electrolyte imbalances. When the body has an abnormal amount of aldosterone, your dog is likely not getting the correct signals telling them how much water they need.
This can lead to increased thirst and urination — another potential early sign of Addison’s disease in dogs. In general, a dog with increased thirst should always be examined, as this can also be a sign of other serious conditions like kidney disease or diabetes,
Skin Abnormalities
Some dogs may show signs of Addison’s on the outside, especially when it comes to skin abnormalities. Skin changes and issues related to Addison’s will look different from other issues, like canine atopic dermatitis, often showing up in the form of hyperpigmentation (dark spots).
Regularly checking your dog over can help you recognize these skin changes before they develop a more severe form of the disease. Plus, it’s just a good rule of thumb and a way to ensure your pet stays healthy for as long as possible.
How Can You Treat Addison’s?
We may not know what causes Addison’s disease in dogs can be treated, but the good news is that it can usually be successfully treated — many dogs with the condition continue to live long, happy lives.
It all starts with getting an appropriate diagnosis, which must be done through your veterinarian.
An ACTH stimulation test is one of the most common diagnosis techniques. This blood test involves injecting your dog with a small amount of ACTH (adrenocorticotropic hormone) and then measuring their cortisol levels. To rule out other issues, many veterinarians recommend other diagnostic tests like electrocardiograms (ECGs), x-rays, or MRI or CT scans.
Keep in mind that Addison’s disease in dogs is still a fairly rare condition, and all signs that point to the disease may be symptoms of a different health issue. If your dog is diagnosed with Addison’s, the next step is to discuss treatment options.
In general, treatment involves injectable treatments made specifically for Addison’s patients, which will usually need to be administered by your vet every three to four weeks. These treatments help replace missing aldosterone and are often prescribed in tandem with an oral glucocorticoid.
Oral medication combinations can also be used without the injectable component. Some dogs, especially those that develop Addisonian crisis, may also require hospitalization and fluid therapy to correct issues like low sodium and prevent shock.
Keeping your dog’s stress level low can also be beneficial in managing the symptoms of the disease. Remember, with Addison’s disease in dogs, even a little bit of stress can set them over the edge.
Paying attention to their stressors, keeping them out of situations that are likely to make them anxious, and helping manage their stress level with natural products like CBD may help keep them safe while the medications are working. Plus, lower stress can mean a stronger immune system.
The Bottom Line
Addison’s disease in dogs may be a scary-sounding diagnosis, but with proper management, many dogs go on to lead long, healthy, normal lives. Although the symptoms of the disease are often vague (earning Addison’s the title of the “great imitator”), staying vigilant with your dog’s health can help you more quickly identify anything out of the ordinary.
That way, you can get your dog the treatment they need so they can remain your best buddy for as long as possible.
Sources:
Disorders of the Adrenal Glands in Dogs – Dog Owners | Merck Veterinary Manual
Addison’s Disease Can Be Fatal To Dogs, Expert Says | Texas A&M Today
Addison Disease – Endocrine System | Merck Veterinary Manual
