Adrienne is a certified dog trainer, behavior consultant, former veterinarian assistant and author of Brain Training for Dogs.
Adrenal Gland Issues in Dogs
You may have never paid much attention to your dog's adrenal glands until they started to cause your dog trouble, making them feel under the weather and miserable.
In humans and dogs, the adrenal glands (also known as suprarenal glands because they sit on top of the kidneys) are responsible for many important functions essential for life. In particular, the adrenal glands produce mineralocorticoid aldosterone, which helps regulate blood pressure and electrolytes (salt, potassium, chloride) and glucocorticoid cortisol which is released during periods of stress and in response to episodes of low blood sugar.
When working well, your dog's adrenal glands ensure that everything is running smoothly. When the adrenal glands stop working as well as they should, too little adrenal gland hormone may be produced, leading to a medical condition known as Addison's disease, also known as hypoadrenocorticism.
The underlying reason why the adrenal glands may no longer work as they should may stem from several factors:
- Autoimmune conditions (immune system mistakenly destroys some of its own adrenal tissues)
- Certain forms of cancer
- Abrupt discontinuaton of steroids (hence, why it's so important weaning dogs off prednisone)
When the adrenal glands are damaged, a cascading chain of events may occur which may lead to several symptoms. These symptoms are often not readily recognized until they worsen over time and lead to what is known as an Addisonian crisis.
Addison's Disease: "The Great Pretender"
In the medical field, the term pathognomonic is used to describe a symptom that is specifically characteristic of a particular disease or condition. For instance, among humans, a sharp pain migrating to the right lower quadrant of the abdomen is often pathognomonic of appendicitis.
When it comes to Addison's disease, this disease is often far from producing symptoms that are pathognomonic. Addison's disease in humans and dogs is known for causing vague symptoms which may mimic the clinical signs associated with several other diseases, and is befittingly nicknamed "the great pretender."
Signs seen in dogs suffering from Addison's disease include:
- Weight loss
- Loss of appetite
- Intermittent vomiting and diarrhea
- Increased drinking and increased urination
- Episodes of weakness
Due to the vague symptoms and the fact that there are several more common disorders causing these symptoms, many vets fail to promptly diagnose Addison's disease in dogs assuming it's something else more common.
Dogs suffering from Addison's disease are often mistakenly diagnosed as suffering from inflammatory bowel disease, hemorrhagic gastroenteritis, pancreatitis, and acute or chronic kidney failure. This leads to dog owners spending lots of money on the wrong diagnostic tests and treatments while also losing precious time.
Owner Complaints With Percentage Based on Frequency
Loss of appetite
Signs of an Addisonian Crisis in Dogs
The symptoms of Addison's disease in dogs tend to be vague, waxing and waning, and progress slowly; they are often ignored until a stressful event takes place (such as boarding the dog in a kennel or moving) which will cause the disease to finally "come to a head."
At that breaking point, symptoms progress and become much worse leading to what is called an Addisonian crisis, or acute adrenal insufficiency. The signs of an Addisonian crisis tend to be prominent and often lead to an emergency vet visit or a trip to the emergency hospital. Typically, affected dogs will develop the following symptoms:
Loss of Appetite
Affected dogs will refuse to eat. This lack of appetite may take place hours or days prior to the time things progress and dog owners seek veterinary intervention.
Severe Vomiting and Diarrhea
Dogs suffering from an Addisonian crisis may develop severe abdominal pain along with vomiting and diarrhea. Dogs may vomit several times. Vomiting was witnessed in 68 percent of dog owners when their dogs developed a crisis, according to the above chart by Feldman and Nelson referenced above.
Diarrhea may be severe as well with dogs presenting with bright red, fresh blood in dog stool (hematochezia) or digested blood in the stool (melena), typically presenting as dark, tarry diarrhea.
Dehydration (Loss of Fluids)
When the dog's adrenal glands no longer work as they should, there will be a deficiency in aldosterone which, as we have seen previously, is responsible for keeping the dog's electrolytes in check.
With less aldosterone, therefore, the body excretes large amounts of sodium while potassium is retained. Affected dogs develop low sodium (hyponatremia) and high potassium (hyperkalemia). When too much sodium is lost and the dog vomits a lot and has diarrhea, the dog becomes dehydrated.
Dehydration may be recognized in dogs by lifting the skin over the neck and/or shoulders. In well-hydrated dogs, the skin will spring back quickly; in a dehydrated dog, it will be slow to go down or even worse, remains lifted. Dehydrated dogs may also develop sunken eyes.
Profound Muscle Weakness
Potassium plays a big role in the correct functioning of many muscles including skeletal muscles and the muscles of the heart. When potassium levels are impacted, this may lead to suppression of the electrical activity of the muscles which causes muscle cramps and muscle weakness.
Shaking is a symptom that is reported by some dog owners witnessing an Addisonian crisis in their dogs. The dog may shake as if feeling cold. Shaking can be triggered by low blood glucose levels.
Slow Heart Rate
A slow heart rate, medically known as bradycardia, is a symptom associated with an Addisonian crisis in dogs and it is due to the increased levels of potassium. Correct levels of potassium are important for maintaining a healthy heart rhythm. When the levels of potassium spike to a dangerous level, the electrical activity of the heart muscles can be severely impacted and may lead to a slow, weak or irregular pulse and even cardiac arrest.
Low Blood Pressure
Sodium plays the important role of helping maintain normal blood pressure. With lower sodium levels, dogs may develop low blood pressure due to renal sodium wasting and potassium retention.
Because good circulation allows oxygen-rich blood to reach a dog's tissues, when a dog develops low blood pressure, the gums may become pale which signals an emergency situation.
Low Blood Sugar
Cortisol plays a role in the regulation of blood sugar; in a dog suffering from Addison disease, the blood glucose may get too low. This can cause a cascading chain of events. In atypical hypoadrenocorticism, dogs may develop weakness and even seizures as a result of low glucose levels.
As a consequence of muscle weakness and potential dizziness which can take place during an adrenal crisis, dogs may stumble, stagger, and appear confused. Slow, uncoordinated movements may also result and further complications affecting the entire body may cause a dog to eventually collapse.
A drop in sodium levels in the body can lead to devastating hypovolemic shock. Hypovolemic shock means that the fluids in your dog's body drop decreasing the dog's overall blood volume.
Emergency Treatment for Addisonian Crisis in Dogs
If your dog ever develops symptoms of an Addisonian crisis, see your vet immediately. If left untreated, this condition can quickly turn lethal. Upon presentation, your vet will work on treating the hypovolemic shock and other signs of illness as soon as possible. The primary goal is treating the shock, and treatment typically takes precedence even before performing an ACTH stimulation test to confirm a diagnosis of underlying Addison's disease.
- Treatment primarily involves fluid therapy so to correct the dog's dehydration and low sodium and high potassium levels.
- Glucocorticoid therapy will include often the intravenous administration of dexamethasone sodium phosphate, and once the dog is stable, dog owners can administer steroids orally.
- Mineralocorticoid therapy may include fludrocortisone acetate (Florinef) may be administered. Another treatment option is desoxycorticosterone pivalate (DOCP), also known as Percorten, given subcutaneously or intramuscularly every 21 to 28 days.
- Routine checks of the dog's electrolyte levels should be scheduled as to monitor any electrolyte changes that may suggest changes in therapy.
Therapy for Addison's disease in dogs is long-term, meaning for the rest of the dog's life. Although Addison's disease along with Addisonian crisis in dogs can be very scary, the good news is that once the dog is stabilized, the prognosis can be good to excellent. This also depends on the dog owner's compliance and education along with a willingness to follow the recommended therapy, explains veterinarian Dr. Marie E. Kerl a board-certified veterinarian specializing in internal medicine.
- Feldman EC and Nelson RW Canine and Feline Endocrinology and Reproduction. Philadelphia WB Saunders 1987
- Veterinary Partner: Addison's Disease (Hypoadrenocorticism)
- Textbook of Veterinary Internal Medicine, by Stephen J. Ettinger, DVM, DACVIM, Edward C.Feldman, DVM, DACVIM and Etienne Cote, DVM, DACVIM
This article is accurate and true to the best of the author’s knowledge. It is not meant to substitute for diagnosis, prognosis, treatment, prescription, or formal and individualized advice from a veterinary medical professional. Animals exhibiting signs and symptoms of distress should be seen by a veterinarian immediately.
© 2018 Adrienne Farricelli
Casey on June 11, 2018:
My 6 year old dog was in addisionain crisis on Friday and was put on fluids all weekend they we took him home with his meds but he hasn't eaten yet. I've been given him puppy milk water and force feeding him chicken. Is this common for him to still be off his food and still very weak
Adrienne Farricelli (author) on April 08, 2018:
Thanks Larry, with my dogs getting older, I need to be on the lookout for conditions as such. My dog is suffering from bouts of irritable bowel syndrome according to my vet, but I think Addison should be screened out with a baseline cortisol test just to be safe.
Larry W Fish from Raleigh on April 08, 2018:
Thanks for such an informative article, Adrienne. There is so much that a dog owner has to look out for that they have no idea about.I love reading about articles such as this to keep me informed.