Addison's disease in dogs

10 January 2024 - 6 min read

The information in this article has been reviewed by Dr. Jennifer Coates on 9 January 2024. Although it may provide helpful guidance, it should not be substituted for professional veterinary advice.

Sick dog

What's Addison's disease in dogs?

Addison's disease—also called adrenal insufficiency or hypoadrenocorticism if you want to be really fancy about it—occurs when a dog’s adrenal glands don’t produce enough hormones called cortisol and mineralocorticoids.

When these hormones are low, your pooch can experience a whole host of health problems. But with the right knowledge and care, dogs with Addison's disease can lead happy, long lives.

Causes of Addison's disease in dogs

Addison's disease in dogs usually stems from a mix of genetic factors. Certain breeds, like Poodles, West Highland White Terriers, and Portuguese Water Dogs, have a higher genetic predisposition to the condition.

Image of a brown Poodle laying down and looking at the camera

Most commonly, canine Addison's disease is caused by an auto-immune response, where your pup’s immune system mistakenly attacks its adrenal glands instead of protecting them.

In rarer cases, certain types of cancer, trauma, or the overuse of drugs like prednisone, mitotane, or trilostane can be involved.

The disease commonly appears in young to middle-aged dogs, often between the ages of four and seven. However, it can occur in dogs of any age.

There may also be a tendency for female dogs to be more susceptible than males, though male dogs can certainly get it as well.

Addison's disease in dogs: symptoms

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When it comes to Addison's disease, a swift diagnosis can mean the world to your pup. Catching the illness early on allows for effective management and a better quality of life.

The tricky part? The symptoms can be pretty subtle and mimic many other health issues.

Early signs of Addison's disease in dogs

Here are some signs of Addison's to look for:

  • Lethargy: Your normally energetic pup might seem unusually tired or sluggish.

  • Gastrointestinal issues: nausea, vomiting, diarrhoea, and a loss of appetite are common.

  • Weight loss: Unexplained weight loss can be a sign of the disease.

  • Increased thirst and urination: If your dog is drinking more water and needing more bathroom breaks than usual, that’s a possible red flag.

  • Shaking or weakness: Pay attention to any unusual trembling or weakness.

Remember, these symptoms can come and go, which makes Addison's disease a bit of a sneaky adversary. If your dog is showing any of these signs a trip to the vet is a good idea.

Even if they don’t have Addison's disease, they might be suffering from a different health condition. Either way, your vet can help you get to the bottom of things.

Diagnosing Addison's disease

german shepherd lays on table with paws outstretched while female owner and vet comfort it

Diagnosing Addison's disease takes a bit of detective work. Since the symptoms can be vague and similar to those of other conditions, your vet will need to do some thorough investigating.

The first step usually involves routine blood and urine tests. These can reveal electrolyte imbalances and other clues that point towards Addison's. But these tests alone aren't enough to confirm the diagnosis.

The ACTH stimulation test

The definitive test for Addison's disease is the ACTH stimulation test. This involves giving an injection of synthetic ACTH (a hormone) and measuring your dog’s adrenal response. In dogs with Addison's, the adrenal glands won't respond as expected, which confirms the diagnosis.

The ACTH stimulation test isn’t 100% perfect; sometimes it can give false positive or false negative results, but this isn’t all that common.

The full picture

Still, to get the full picture, vets don't just rely on this one test. They look at everything—symptoms, blood tests, the dog's history—and then use the ACTH test results and results from other tests, if necessary, to piece it all together. Remember, diagnosing Addison's disease can take time and may require multiple tests. Patience and close communication with your vet are key during the whole process.

Addison's disease treatment options

poodle sitting on tan carpet and looking at man sitting on couch holding book

Once your vet diagnoses Addison's disease in your dog, it’s time to start managing the condition. Thankfully, treatments for Addison's disease tend to be extremely effective, especially with early intervention. Here's what treatment may involve:

Hormone replacement therapy

Hormone replacement therapy is the backbone of managing Addison's disease in dogs. This involves administering medications that mimic the natural hormones usually produced by the adrenal glands that help control electrolyte levels.

The most commonly used drug is DOCP (deoxycorticosterone pivalate), administered through injections every 25–30 days. Fludrocortisone is an oral medication that can be a good option as well.

While DOCP injections are often given by a veterinarian, dog owners can be taught to administer them at home, under the close guidance of their vet. Meanwhile, oral medications may also be prescribed to replace cortisol, another crucial hormone.

This careful replacement helps maintain a delicate hormonal balance, helping your dog's body function as closely to normal as possible.

Fine-tuning medication dosages

Finding the right balance of medication is a delicate process that varies from dog to dog.

Initially, your vet will likely start with a standard dose—adjusted based on factors like weight, overall health, and the severity of their condition—and then closely observe your dog.

Regular follow-up visits are critical during this phase; your vet may need to adjust the medication dosage or frequency depending on how they respond.

Ongoing monitoring

Regular check-ups and blood tests are key to managing Addison's disease.

These tests help your vet monitor how your dog is responding to treatment and the levels of electrolytes in your dog’s body, making sure they stay within a healthy range.

This testing helps your vet catch any potential problems early, allowing for timely treatment adjustments.

Preparing for an Addisonian crisis

Old dog

An Addisonian crisis is a medical emergency that requires immediate attention.

It occurs when your dog’s cortisol and mineralocorticoid levels drop to dangerously low levels, potentially leading to severe symptoms like shock, collapse, or even death if not treated promptly. It’s extremely important to know the signs of an Addisonian crisis and to have a plan for swift veterinary care.

An Addisonian crisis requires immediate treatment. Your vet will need to administer intravenous fluids to address issues like dehydration and electrolyte imbalances and give your dog medications to address low cortisol levels. Certain medications can be used to stabilise the heart rate and blood pressure.

If you can’t immediately see your usual vet, you’ll need to get to an urgent care clinic or an emergency vet. Remember, an Addisonian crisis can be a life-or-death situation for your pup.

Atypical Addison’s disease

In some rare cases, when dogs show signs of Addison's disease, their blood tests don’t show the usual changes in electrolytes. This is known as 'atypical' Addison's disease, which develops when dogs have low cortisol levels but are not low in mineralocorticoids.

Dogs with atypical Addison’s disease require treatment to replace their missing cortisol, usually with a drug called prednisone. Initially, they don’t need mineralocorticoid replacement hormones, but this can change as time goes on, so their electrolyte levels should be monitored.

Atypical Addison's can be harder to spot than typical Addison’s. Its symptoms can be subtler, like occasional lethargy, mild stomach issues, and weakness, but an ACTH stimulation test should still lead to an accurate diagnosis.

Living with Addison's disease

Happy Brazilian man going on a road trip with his dog and putting the bags in the trunk

Caring for a dog with Addison's disease requires dedication, but it can be deeply rewarding. It's all about establishing a new normal that lets your furry friend lead a comfortable and joyful life.

The most important thing is to maintain a consistent medication routine for your pup. Your dog’s hormone replacement therapy, in particular, is what keeps their hormone levels balanced and prevents their symptoms from flaring up.

Regular veterinary check-ups are also crucial. These visits allow for ongoing monitoring of your dog's health, necessary adjustments to their medication, and routine blood tests.

While there's no specific diet required, you should make sure your dog is eating balanced, nutritious meals. Moderate, consistent exercise is important as well. At the same time, you should avoid activities that are too strenuous.

Indeed, minimising stress is generally important for a dog with Addison's disease. This means creating a stable, calming environment at home and avoiding sudden changes that could cause anxiety or distress.

Regular, comforting interactions and play can help keep your dog relaxed and happy. When a stressful event is unavoidable, your veterinarian may recommend that you give your dog extra prednisone to help their body react appropriately.

The bottom line

With early detection, proper management, and consistent care, Addison's disease doesn’t have to spell doom and gloom for your pup.

Treatment, though lifelong, is generally very effective. With hormone replacement therapy and regular monitoring, most dogs with Addison's disease maintain a good quality of life.

It’s also worth noting that the costs of these medications can be quite high, especially for larger dogs. This is where dog insurance becomes invaluable. Insuring your dog while they’re still young and healthy before any pre-existing conditions like Addison's disease are diagnosed, will help you get reimbursed for expensive veterinary care.

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David Teich
Lead Content Editor

David Teich is Lead Content Editor at ManyPets. He loves pets, Scrabble, Oxford commas, and typing loudly.