Canine Addisons Disease: A guide to Hypoadrenocorticism

Canine addisons disease is also known as (hypoadrenocorticism) and develops when a dog or puppy’s adrenal glands stop working properly. This disease is a serious health condition and will need you to take your pooch to the vet immediately.

The adrenal glands have a very important function inside a dog’s body. They are part of the Endocrine System and can be found next to the Kidneys. Alongside other important functions they help to produce three very important hormones including (glucocorticoids, catecholamines and mineralcorticoids).

Each of these hormones have different functions within the body. The glucocorticoids (which include Cortisol) help deal with inflammation and stress. The catecholamines produce adrenaline which enables dogs cope with danger (by producing the natural ‘fight or flight response). The mineralcorticoids help the body produce sodium and potassium.

What are the causes of the condition…

Canine Addisons Disease is caused by the adrenal glands not producing enough cortisol – there are a number of reasons why the adrenal glands stop producing enough cortisol including…

  1. Adrenal gland tumors.
  2. A tumor affecting the pituitary gland.
  3. An infection of the adrenal glands.
  4. Hemorrhaging, injury or trauma to the adrenal glands.
  5. Due to your dog or puppy being exposed to steroids for too long.
  6. Medication stopped too suddenly and not over a period of time.
  7. Fungal infections.
  8. Cancer.
  9. Genetics -the condition can be inherited.
  10. Canine Addisons Disease is actually more common in females than males and is thought to affect certain breeds including, Labrador Retrievers, Portuguese Water Dogs, Standard Poodles, Great Danes and Bearded Collie.

There are Three Types of Canine Addisons Disease

Primary – This due to your dog or puppy not producing enough mineralcorticoids and glucocorticoids.

Secondary – This is when the pituitary glands don’t produce enough adrenocorticotropic hormone – also known as ACTH. This is essential for the adrenal glands to be stimulated enough for them to produce enough hormone.

Atypical – This is when the adrenal glands have been damaged which has also affected the imune system.

Symptoms of Canine Addisons Disease

The symptoms of this condition can include…

  1. Vomiting
  2. Weakness specifically related to your dog or puppy’s muscles
  3. Diarrhea
  4. Shaking
  5. The pulse may become weaker
  6. Appetite loss
  7. Irregular heart beats
  8. Shock
  9. Collapse and even death
  10. Depression is a very common symptom

Death will occur when the sodium levels in your dog’s blood have become dangerously low and the potassium levels too high – this cause the blood pressure to fall which can then lead to death.

Diagnosis…

Addisons disease can be hard to diagnose because the symptoms can be fairly vague. This can sometimes lead vets to misdiagnosing the condition as an infectious disease, kidney disease or even digestive problems.

If the condition is not diagnosed quickly then the affected dog can become very ill very quickly (and can die). Dogs left undiagnosed and therefor untreated can develop hypotension (low blood pressure), abnormal elect

There are various methods that can be utilised to diagnose this condition. Below are a few of the methods used by Vets. The first thing that medical professionals will often do is to evaluate blood tests on a regular basis.

  1. By testing the blood tests for the electrolyte levels this will help determine the sodium and potassium levels. In dogs with Addisons Disease the potassium levels tend to be higher and sodium levels lower.
  2. ACTH Tests will often be undertaken – which measures the functioning of the adrenal glands
  3. ECG or EKG – This will test to see how the heart is functioning and how fast or slow the heart is beating.
  4. Kidney function tests will also be undertaken. This will help determine blood urea levels (the levels maybe higher in dogs with the condition). The reason for this is due to restricted blood flow. If the affected dog is given fluids this can rectify the problem.
  5. By performing blood tests this will also help to determine if the affected dog is anemic. Anemia can be caused by a lack of Cortisol (which can then supress the bone marrow).
  6. Some dogs can also develop hypoglycemia (this is because Cortisol is an important factor in the production of Glucose). So this can lead to low blood sugar levels.
  7. Another diagnostic test is the ACTH stimulation test (this is also used to diagnose Cushings Disease). If a dog does have Addisons the Cortisol levels tend to be much higher after they have had the ACTH injection.

How is Addisons Disease Treated…

The treatment for this condition will include drugs and medications to help replace the hormones that your dog isn’t producing including…

  • Percorten V – in collaboration with Prednisone which will help replace the cortisol that your dog’s adrenal glands are not producing.
  • Oral medication like – Fludrocortisone acetate. This is the difficult part of the treatment process i.e. replacing the mineralcorticoids. This is why Fludrocortisone acetate maybe prescribed (to help regulate the electolyte levels).
  • Your dog may have to have intravenous fluids injected including electrolytes and corticosteroids.
  • Previously injections of desoxycorticosterone privalate (DOCP) have been utilised to control Addisons disease.

Herbal Remedies…

Speak to your vet before you use any herbal remedies but the following remedies are sometimes used as a holistic approach…

Slippery Elm – This is a great treatment to cure diarrhea in dogs and puppies.

Valerian – This is a good herbal treatment for blood pressure.

Milk Thistle – This is a great antioxidant and helps to support your dog or puppy’s immune system.

Arsenicum 30 C – This supports your dog;s urinary system and and dehydration and thirst that your dog or puppy may be experiencing.

Ginger – This herb is often used to reduce your dog’s blood pressure and strengthen your dog’s heart.


References:

Ackerman, L. 1995. Owners Guide to Dog Health.

Bleby, J and Bishop, G. 2003. The Dogs Health from A to Z. A David Charles Book.

Bordwell, S. 1994. The American Animal Hospital Association Encyclopedia of Dog Health and Care. Quill.

Eldredge D and Thornton, K. 2005. The Everything Dog Health Book. Adams Media.

Useful links: www.wikipedia.com



Did you know…?

1. The image above (courtesy of Gray’s Anatomy) is a picture of the adrenal cortex under high magnification.

2. Did you know that dogs with Whipworms can exhibit similar symptoms to dogs suffering from Addisons Disease.

3. In very severe cases a dog can develop what is known as an Addisonian Crisis. This is when the potassium levels get so high that the heart starts to suffer.

4. The Adrenal Glands are also known as the Suprarenal Glands (which simply means ‘above the kidney’).

5. Each of the Adrenal Glands has an ‘inner’ and ‘outer’ cortex.

The Pituitary Gland…


As previously mentioned Tumors affecting the Pituitary Gland can also lead to Addisons Disease. But what does the Pituitary Gland actually do?

The Pituitary Gland consists of two sections each of which are located at the base of the dog’s brain.

This gland is vital as it helps to control how the adrenal glands and thyroid work (think of it as the Pituitary gland sending the orders to the adrenal glands and thyroid which enables them to work effectively). It is the front of the Pituitary Gland that sends the orders (known as the Anterior part of the Pituitary).

The posterior part of the Pituitary Gland is far less active. The posterior part of the gland helps to produce Oxytocin which helps to stimulate uterine contractions when dogs are in labour and to also support milk production. The posterior part of the gland also helps with the production of an antidiuretic hormone that helps regulate how much water is absorbed by the kidneys.