In this video Dr. Karen Becker talks about Addison's disease, also known as hypoadrenocorticism.
Addison's is a disease of the adrenal glands and is diagnosed most often in female dogs between the ages of four and seven.
Listen as Dr. Becker discusses the causes and treatment of Addison's and offers several tips on how to prevent the condition from developing in your own dog.
Today I want to discuss Addison's disease, also known as hypoadrenocorticism.
Addison's disease is a condition in which the adrenal glands produce fewer corticosteroid hormones than the body requires.
Your dog's adrenal glands sit on the pole of the kidneys and secrete several different hormones.
The adrenals are most well-known for producing the hormones responsible for an animal's fight-or-flight response, which is how the body copes with potential danger or a perceived impending stressor.
The Stress Response
In phase one of the adrenal or stress response, called the adaptation phase, the body intermittently secretes a slightly higher level of cortisol in response to a slightly higher level of stress.
This stress could be the result of being stuck in a crate all day, having an unaddressed physical injury, or something along those lines.
Phase two of the stress response is called the alarm phase, and it occurs when the stressor is significant or constant enough to cause excessive levels of cortisol to be produced. This happens, for example, when a dog is in a life-threatening situation.
Because these potent stress hormones are meant to be secreted in small amounts only when the body is being threatened, in theory, animals should experience periods of non-stressful living to recover from the side effects of stress-induced hormones.
But when production of these hormones continues on a daily basis, hyperadrenocorticism is the result. This condition, commonly known as Cushing's disease, is a very common problem in pet dogs.
When the adrenal glands become overworked and can no longer produce all the hormones the body is asking for, phase three of the stress response occurs. This phase is called adrenal exhaustion.
If the adrenals continue to under-produce stress hormones, adrenal insufficiency – otherwise known as Addison's disease – develops.
Types of Addison's Disease
There are actually three types of Addison's disease – primary, secondary and atypical.
Cortisol is a corticosteroid produced by the middle layer of the adrenal gland and it acts on sugar, fat and protein metabolism in a dog's body. Corticosteroids, remember, are responsible for the fight-or-flight response and play a huge role in an animal's ability to adapt to stressful situations.
When cortisol is under-produced, even the smallest amount of stress can result in physiologic disaster for the dog.
The mineralocorticoids, one of which is aldosterone, are produced by the outside layer of the adrenal gland, and their job is to regulate electrolytes like sodium and potassium.
Typically, both the middle and outer layers of the adrenals begin to under-produce hormones, which is what leads to primary Addison's disease.
If only the middle layer fails, meaning the adrenals are still producing electrolyte balancing hormones, the condition is known as atypical Addison's disease.
A common root cause of both the primary and atypical forms of the disease is immune-mediated damage to the adrenal glands. This is a situation in which the dog's immune system attacks the adrenal tissue.
Although it is rare, adrenal gland failure can also occur due to infection or tumor of the glands, or even death of adrenal tissue due to obstruction of the blood supply.
Secondary Addison's is caused by failure of the pituitary gland or the hypothalamus, both of which act on the adrenals, but in different ways.
Addison's Disease versus Cushing's Disease
Addison's is the opposite of Cushing's. I did a 3-part video series on Cushing's disease last year.
While Cushing's is caused by overproduction of adrenal hormones, Addison's is the result of failure of the adrenal glands to secrete enough hormones.
The good news is Addison's is far less common than Cushing's in dogs, and is extremely rare in cats.
Addison's is most commonly diagnosed in young and middle-aged female dogs, though any age or breed can develop the condition.
From 70 to 85 percent of dogs with Addison's disease are female and between the ages of four and seven. Some breeds seem more at risk for the disease than others, including Great Danes, Portuguese water spaniels, Rotties, standard poodles, Westies, and Wheaten terriers.
Symptoms of Addison's Disease
Symptoms of this condition can appear suddenly and be quite severe, or they can happen on and off with varying levels of severity.
Addison's symptoms can be quite vague and include weakness, depression, loss of appetite, vomiting, diarrhea, and sometimes increased thirst and urination.
Addison's is often referred to as the great imitator or great pretender because it is often misdiagnosed as kidney failure or a case of an animal just not feeling quite right.
Symptoms can also mimic an insulin-secreting pancreatic tumor.
Sometimes there is regurgitation of undigested food. Animals that vomit undigested food are often diagnosed with Megaesophagus, a condition which can be caused by underlying Addison's disease.
So as you can see there are a lot of different symptoms and often a vague presentation of symptoms.
If symptoms are acute, meaning sudden and severe, the situation is called an Addisonian crisis. During periods of stress, dogs will collapse from shock brought on by an imbalance of electrolytes and metabolism.
About 30 percent of dogs with Addison's are diagnosed by an initial Addisonian crisis. And unfortunately, this is sometimes the first sign the pet owner has that a dog is sick or has symptoms of underlying Addison's.
Sometimes, this initial crisis is overwhelming to both the owner and the dog. Most importantly, an Addisonian crisis can be fatal if not treated immediately.
Keep in mind that cortisol helps animals deal with stress. A lack of cortisol in Addison's disease makes dogs less able to manage stress. So pets with the condition are usually more symptomatic when they are in stressful circumstances. And as we know, stressors for our pets can be something as simple as a change in their daily routine.
That's why being boarded, for example, can bring on an escalation of symptoms in a dog with Addison's disease.
In a case of suspected Addison's disease, your vet will look for clinical signs like dehydration, a weak or slow pulse rate, irregular heartbeat, generalized weakness and depression.
Unfortunately, there isn't a quick or inexpensive screening test for adrenal health. Vets can't assess a dog's adrenal function using the normal annual blood panel.
Bloodwork will sometimes show low sodium and high potassium levels, but in the case of secondary and atypical Addison's, these electrolyte levels may not be affected.
Creatinine and BUN levels can be affected, and sometimes there is low-grade chronic anemia or a blood sugar imbalance.
High potassium levels can cause irregularities in your dog's heart rhythm which can be life-threatening. These abnormalities can be seen on an ECG as a slow, irregular heartbeat.
X-rays of dogs with Addison's are usually normal. Occasionally, the heart may appear smaller than normal or the esophagus may look larger than normal.
The confirming test for Addison's disease is an ACTH stimulation test. In this test, blood samples are taken before and after the dog is injected with an adrenal-stimulating hormone.
If the dog is healthy, the blood cortisol levels will increase. If the dog has Addison's disease, there will be no increase in blood cortisol, which is the confirming diagnosis.
If your dog is very sick, she will need to be hospitalized to receive IV fluids, cortisol replacement agents, and drugs to counteract the effects of too much potassium on the heart.
Treatment of Addison's
Treatment of Addison's disease depends on whether the condition is primary, secondary or atypical. Most often the insufficient adrenal gland hormones need to be replaced – typically these are cortisol and aldosterone.
(I realize the different types of Addison's and the various treatments are confusing, so my hope is this video will help to clarify things a bit.)
If your dog has primary Addison's, which means both layers of the adrenal gland are under-producing hormones, fludrocortisone is usually prescribed.
Your pet's sodium and potassium will be monitored until the correct levels are achieved, which means the right fludrocortisone dose has been reached. Then those electrolytes will need to be monitored several times a year to make sure they are still in the healthy range.
Because Florinef® (the oral form of fludrocortisone) also has glucocorticoid activity, most dogs do not require additional cortisone.
For primary Addison's there is also an injectable drug called DOCP, brand name Percorten V. This is a long-acting drug given by injection every 25 days. The drug is given primarily to regulate electrolytes, so cortisol replacement will also be needed. This means both an injection and an oral daily cortisone drug.
For dogs with atypical or secondary Addison's, only glucocorticoid replacement (Prednisone, for example) is given.
Since dogs with Addison's don't produce enough of their own cortisol to effectively manage stress, keeping your pet's life as stress-free as possible is also a very important part of long-term management of the disease. It is also, in my opinion, a big part of preventing the disease from taking hold.
Holistic veterinarians have an arsenal of adaptogenic herbs, homeopathics, nutraceuticals and other great natural substances that can help improve the quality of life of Addison's dogs.
The goal, of course, is to prevent adrenal exhaustion from happening in the first place.
How You Can Help Prevent Adrenal Burnout in Your Dog
We know that most Addison's dogs were born with healthy adrenal function.
We also know that their adrenals probably didn't suddenly act up and quit working on a specific day. We know these dogs didn't move from healthy adrenal function to poor adrenal function overnight.
What happens is that the body starts to experience less optimal adrenal hormone production over a period of time. Long before the adrenal glands actually fail, there is insufficiency of hormone production and suboptimal adrenal health. This can occur for weeks, months or years before there is an official diagnosis of Addison's disease.
There are some common sense things I recommend to keep your dog from experiencing adrenal burnout:
- Reduce nutritional stress by feeding a balanced, species-appropriate diet.
- Don’t allow your pet to be over-vaccinated. This is hugely stressful to the immune system and can prompt autoimmune reactions.
- Assess your dog’s personality. If you have a high-strung pet that would benefit from calming Ttouch, a form of relaxing massage, consider learning how to do it. If you have a sensitive, reserved dog that doesn’t handle stress well, mitigate periods of unavoidable stress by offering Bach flower essences, adaptogenic herbs, and nutritional support.
- Talk to your holistic vet about glandulars. Glandulars are extracts or freeze-dried glands that nourish specific organs. In the case of Addison’s dogs, I recommend adrenal glandulars. I use Standard Process glandular formulas with phenomenal success.
- Make sure your dog is getting adequate exercise and rest, both of which help support healthy cortisol levels in the body.
Unfortunately, endocrine diseases are becoming more prevalent in veterinary medicine.
Addressing predisposing factors, reducing physiologic and environmental stressors, and recognizing symptoms of adrenal insufficiency are all important factors in helping dogs avoid a diagnosis of Addison's disease.