Addison's Disease in Dogs
Addison’s disease negatively affects a dog’s ability to appropriately respond to stress and causes a generalized dysfunction of many organ systems. As a potentially life-threatening condition, understanding the symptoms and the risks, especially in dogs predisposed to developing Addison’s Disease, can make the difference between a good prognosis and a poor prognosis.
In This Article
What is Addison's Disease
What Is Addison's Disease In Dogs?
Addison's Disease, also known as Hypoadrenocorticism, is an endocrine (hormonal) disorder that occurs most commonly in young to middle-aged female dogs, although male dogs can also develop Addison’s disease. Dogs with Addison’s disease are unable to produce an adequate amount of cortisol, which affects their ability to appropriately respond to stress, along with causing the dysfunction of multiple organ systems. Addison’s disease may also interfere with the ability to regulate important electrolytes, especially sodium and potassium.
Signs & Symptoms Of Addison’s Disease In Dogs
Symptoms of Addison’s disease vary and are often hard for owners to catch until it’s severe. These may include:
Decreased heart rate
Low blood pressure
In many cases, the signs of Addison’s disease can be nonspecific, like lethargy, vomiting, diarrhea, decreased appetite, and weight loss. Dogs with Addison’s disease can also experience decreased heart rates with possible heart arrhythmias, which results in poor circulation, and kidney damage secondary to high potassium levels. Many dogs with acute Addison’s disease also have low blood pressure and dehydration.
Decreased production of mineralocorticoids leads to most of the symptoms of Addison’s disease in dogs. A less common form of Addison’s, called “atypical Addison’s,” results from a drop in production of glucocorticoids, which occurs with decreased production of glucose and increased sensitivity to insulin, resulting in low blood sugar.
What Causes Addison's Disease In Dogs?
Dogs develop Addison’s disease through two main processes: autoimmune disease and decreased ACTH production by the pituitary gland.
Decreased pituitary gland function
The primary form of Addison’s disease in dogs is an autoimmune disorder that results in the destruction and atrophy of all three layers of the adrenal cortex. The less common type, atypical Addison’s, is caused by inadequate ACTH production by the pituitary gland, which can have a variety of causes in itself.
Young to middle-aged female dogs have Addison’s disease most commonly, while some breeds are predisposed to it. These include Standard Poodles, Great Danes, West Highland White Terriers, Portuguese Water Dogs, Bearded Collies, and several other breeds. In many cases, however, the cause of Addison’s disease is unknown.
Diagnosing Addison’s Disease in Dogs
Addison’s disease in dogs is diagnosed through blood work. Veterinarians look for specific chemistry changes, such as high potassium, low sodium, signs of kidney dysfunction, low blood glucose, metabolic acidosis, an absence of a stress leukogram (CBC), and anemia.
If Addison’s is suspected, some veterinarians will recommend beginning with a baseline cortisol level test, which measures cortisol levels. If the results suggest Addison’s, your veterinarian may suggest confirming the diagnosis with an ACTH stimulation test.
What Is An Addisonian Crisis?
By the time most owners become aware that something is wrong with their dog, Addison’s disease is a medical emergency. This is called an Addisonian crisis, or adrenal crisis, which requires immediate veterinary attention and hospitalization. A dog suffering an Addisonian Crisis can be struck with sudden weakness, severe vomiting, diarrhea, and in extreme cases can even collapse.
Treatment For Addison's Disease In Dogs
Once diagnosed with Addison’s Disease, most dogs are able to be successfully treated. Veterinarians begin fluid therapy along with supplemental medications, perform necessary diagnostics, like blood work, and administer a steroid to assist with the initial shock. In severe cases, mineralocorticoid replacement therapy may also be started to help patients with extremely high potassium or low sodium to alleviate the secondary effects. Overall kidney function, electrolytes, and blood glucose are also closely monitored to ensure an appropriate response to therapy.
For long-term treatment of Addison’s disease, your veterinarian may prescribe a mineralocorticoid supplement in the form of an injection of DOCP (desoxycorticosterone pivalate). This injection is administered approximately every three to four weeks based on the dog’s response. Your veterinarian may also measure your dog’s electrolytes during the second injection to assess the response to the treatment and determine the best timespan for future injections.
In addition to the injection, your dog will likely need a daily administration of a steroid called prednisone. This acts as a supplement for the deficient glucocorticoid and helps control clinical signs. Occasionally, dogs do not require this supplementation, although the vast majority do. Your veterinarian will determine whether your dog requires it, and if so, the duration of administration. For example, some dogs require prednisone for the rest of their lives, while others only need it during stressful circumstances, like boarding or surgery.
Is There A Cure For Addison’s Disease In Dogs?
No. The goal of treatment for this disease is managing the levels of steroids in the bloodstream to decrease the risk of recurring Addisonian episodes, but there is no cure.
Is Addison’s Disease Contagious For Humans or Other Pets?
Addison’s disease is not contagious to humans or other pets.
What is the cost of treating Addison’s Disease in Dogs?
The cost of treating Addison’s disease will depend on the severity of the initial Addisonian crisis and your dog’s response to medication. You can expect to pay for the initial hospitalization and any complications that arise, like kidney dysfunction, as well as medication. Since Addison’s disease is a lifelong condition, you will most likely be paying for medication and veterinary visits for the remainder of your dog’s life.
Recovery and Management of Addison’s Disease in Dogs
Recovery from Addison’s disease is dependent on the severity of the case at the time of presentation. Except for severe cases, overall recovery prognosis is positive. You can expect to manage your dog’s Addison’s disease for the rest of his life with medication. Without steroids, dogs relapse, and you will also need to take your dog to the veterinarian for monitoring.
Monitoring consists of checking serum electrolytes (sodium/potassium levels) along with standard blood work. These tests check to see if the medication is at an appropriate dose or if adjustments need to be made. Once your dog is stabilized, veterinarians recommend measuring electrolyte levels every three months for the first year after diagnosis and regular check-ups every three to six months.
Preventing Addison’s Disease in Dogs
Unfortunately, Addison’s disease cannot be prevented, except in rare cases where it is the result of a prolonged accidental dose of an adrenal enzyme inhibitor like trilostane, in which case correcting the dosage will prevent an Addisonian episode.
Is there a vaccine for Addison’s disease in Dogs?
Addison’s disease is a hormonal condition. There is no vaccine.
Summary of Addison's Disease In Dogs
Addison’s disease in dogs is a hormonal disorder where they are unable to produce enough cortisol. Common symptoms include lethargy, vomiting and diarrhea. Often, Addison’s disease goes unnoticed until it is a medical emergency. Understanding the signs, symptoms, and treatment options will help you get your dog the veterinary care they need to give them the best prognosis.