Addison’s Disease in Dogs | The Silent Endocrine Disorder

Addison’s disease in dogs is a sneaky condition that messes with your pup’s hormones, and knowing about it could save your furry friend’s life. So, grab a cuppa, and let’s get to know about canine endocrinology – don’t worry, I’ll keep it simple and fun!

What is Addison’s Disease?

Your dog’s body is like a well-oiled machine; the adrenal glands are tiny factories pumping out important hormones. But in dogs with Addison’s disease, these factories go on strike. It’s like the foreman (you) shows up to work, and all the workers have decided to take an extended coffee break.

Addison’s disease, or hypoadrenocorticism if you want to sound fancy at the dog park, is when your dog’s adrenal glands don’t make enough of certain hormones. It’s like they’re running on low battery mode all the time.

Adrenal glands sitting on top of the kidneys are small but mighty. They’re responsible for producing two types of hormones that are super important for your dog’s health:

1. Glucocorticoids (Cortisol): Consider cortisol your dog’s built-in stress manager. It helps them deal with everything from a vet visit to a squirrel chase. It’s also involved in regulating metabolism, so it’s pretty much the multitasker of hormones.
2. Mineralocorticoids (Aldosterone): This is the body’s salt balancer. It keeps your dog’s electrolytes in check, which is crucial for pretty much everything their body does, from keeping their heart beating right to making sure their muscles work properly.

When these hormones are in short supply, it’s like your dog’s body is trying to run a marathon without any fuel or water. They might feel tired all the time, have tummy troubles, or even collapse if things get really bad.

Causes of Addison’s Disease in Dogs

There are two types of hypoadrenocorticism:

1. Primary Addison’s Disease: This is the most common type, and it’s like the adrenal glands decide to take early retirement without giving notice.
2. Secondary Addison’s Disease:  This is when the problem starts in the brain, not the adrenal glands. The pituitary gland, which is like the body’s hormone control center, stops sending the “make hormones” message to the adrenal glands. It’s like the manager forgetting to tell the workers to come in for their shift.
3. Atypical Addison’s Disease: In this version, only some hormones are affected. It’s like a partial power outage in your dog’s body. These dogs might not have the same electrolyte imbalances as other Addisonian dogs, which can make it trickier to diagnose.

Which dogs Are at Risk?

While any dog can get it, some pups are more prone to this hormone hiccup than others. Addison’s disease usually shows up in young to middle-aged dogs. It’s like the canine version of a mid-life crisis, but instead of buying a sports car, their hormones decide to take a vacation. Female dogs are more likely to get Addison’s than boys. 

The most common breeds with Addison’s disease include:

• Standard Poodles 
• Great Danes 
• Portuguese Water Dogs 
• Nova Scotia Duck Tolling Retrievers 
• Bearded Collies 

But remember, any dog can get Addison’s, so don’t rule it out just because your pup isn’t on this list.

Symptoms of Addison’s Disease in Dogs

If your dog suddenly turns into a picky eater or starts treating your carpet like their personal toilet, it could be Addison’s. Look out for:

• Loss of appetite (they turn their nose up at even their favourite treats)
• Vomiting (more than just the occasional hairball)
• Diarrhea (the kind that makes you question why you chose light-coloured carpets)

Behavioural Changes

Has your usually bouncy buddy turned into a couch potato? Addison’s can cause:

• Lethargy (they’re more interested in naps than walks)
• Depression (they’ve lost that spark in their eyes)
• Weakness (they struggle with stairs or jumping on the bed)

Physical Symptoms

Some physical signs to watch for include:

• Weight loss (their collar’s getting looser)
• Increased thirst and urination (you’re refilling the water bowl more often)
• Shaking or muscle tremors (like they’re auditioning for a doggy dance competition)

The Waxing and Waning Nature of Symptoms

Addison’s symptoms can come and go. Your dog might seem fine one day and off the next. It’s like they’re playing a confusing game of “Guess What’s Wrong With Me.” This on-again, off-again nature can make Addison’s hard to spot.

Signs of Acute Adrenal Insufficiency

An Addisonian crisis is when things go from bad to worse, fast. Signs include:

• Severe weakness or collapse
• Vomiting and diarrhoea (often with blood)
• Abnormal heart rate and rhythm
• Low body temperature

An Addisonian crisis is a life-threatening situation. It’s like your dog’s body is shutting down because it can’t handle stress anymore. If you see these signs, don’t wait – get to the vet ASAP. It’s not the time to Google “home remedies” or ask your neighbour’s cousin’s dog walker for advice.

Remember, catching Addison’s early can save your pup from the drama of a full-blown crisis. So keep your eyes peeled for these signs, and don’t hesitate to chat with your vet if something seems off. Better safe than sorry, right?

How Veterinarians Diagnose Addison’s Disease in Dogs

Here are some of the ways vets can diagnose Addison’s disease. These include a complete medical history, a full physical exam, a bloodwork that includes a cortisol test, an ACTH blood stimulation test, as well as a bloodwork that involves a bloodwork that measures low levels of cortisol. The veterinarian will suspect Addison’s disease if the dog’s shock is treated with intravenous liquids and steroids.

A full blood test can show elevated potassium levels and low sodium. Addison’s disease which is atypical or uncommon does not show these changes in electrolytes on blood tests and it’s considered to be a different form of Addison’s. If you have azotemia or elevated kidney enzymes, this can be mistaken for kidney disease. In less common cases, low blood sugar can also mimic an insulinoma, a tumour of the pancreas.

The ACTH Test is used as the primary diagnostic test for Addison’s Disease. This test begins with a sample of blood to determine the cortisol level (stress hormone). Then, an intravenous ACTH dose is administered.

A second blood sample will be taken an hour later to determine how the dog’s response to ACTH was. Addison’s can be diagnosed if your dog has low baseline cortisol and minimal response to stress hormones.

In emergencies, baseline cortisol can be checked. When the dog has stabilized, an ACTH blood test can be performed if they are too low. An abdominal ultrasound can be used to detect small adrenal glands.

Tests that focus on the plasma of dogs include endogenous ACTH, plasma renin, and urine cortisol-creatinine ratio. These patients are usually normal on an ACTH stimulation test.

Blood tests usually show elevated potassium in dog breeds from the Pacific Rim, such as Shiba Inus or Akitas. Whipworm can cause falsely high potassium levels and low sodium, which could lead to confusion in diagnosing Addison’s disease.

Addison’s Disease Treatment in Dogs

Treatment for Addisonian crises focuses on intravenous fluids and steroids. Hypoglycemia, or low blood sugar levels and/or irregular heart rhythms may also require treatment. The majority of dogs recover quickly and completely from treatment.

Addison’s disease treatment involves replacing mineralocorticoids, such as aldosterone (the steroid hormone). This can be done by administering oral medication (fludrocortisone) twice daily or with an injection of DOCP (desoxycorticosterone pivalate) approximately every 25-30 days. Your veterinarian will help you determine the best treatment for your pet based on its diagnosis.

Fludrocortisone is a glucocorticoid with mineralocorticoid properties. Dogs receiving injectable DOCP need additional glucocorticoids (such as prednisone or oral) since the DOCP only has mineralocorticoid activities.

Oral fludrocortisone is preferred by some experts, while others believe DOCP regulates the electrolytes better. However, it comes down to what each veterinarian prefers and which formulation works best for their dog. Some dogs are not able to tolerate injections while other dogs have difficulty taking medication orally. Based on your vet’s diagnosis, they will know what is best for your dog.

Typically, electrolyte and ACTH testing is performed on days 10, 30, and 90 after the start of therapy. After electrolyte concentrations are stabilized, mineralocorticoids can be adjusted. The levels will be checked a couple of times per year to make sure it is the right level for your dog.

If your dog experiences extra stress, the dose of glucocorticoids can be increased. Addisonian dog stress can be caused by veterinary visits or car rides. Pet parents leaving town may also cause it. Increased doses of steroids can help to prevent Addisonian crises, lethargy and other symptoms.

FAQs about Addison’s Disease in Dogs