Addison's disease is a condition in which a dog's adrenal gland does not produce a sufficient amount of either cortisol or aldosterone.This can cause many serious health complications, and has a high probability of being mis-diagnosed as another disease. This is because the symptoms of Addison's disease in dogs are relatively general, including fatigue, diarrhea, sweating, and muscle pain. The most difficult aspect of dealing with Addison's disease in your dog is receiving a positive diagnosis for the disease. After diagnosis, the treatment options for Addison's disease are very effective, though will require your dog to take medication for the rest of their life.
There are several factors that can cause Addison's disease, usually related to improper function of the adrenal glands. The adrenal glands are very important for your dog's overall health, as they produce many important hormones to aid in proper function of your dog's body.
Certain dog breeds are suspected to be more prone to develop Addison's disease. These breeds include Portuguese Water Dogs, Bearded Collies, Standard Poodles, Great Danes, and the Soft Coated Wheaten Terrier. Dogs that have had surgery near the pituitary gland or hypothalamus may also develop Addison's disease (usually Secondary Addison's, since this would be a result of damage to the pituitary gland or hypothalamus). Generally, many cases of Addison's disease are seen in young or middle-aged female dogs. However, dogs of any age or gender are able to develop Addison's disease.
The adrenal gland is made up of two distinct layers, each which are responsible for producing different
types of hormones. The interior layer of the adrenal gland (also called the medulla) is responsible for producing
hormones similar to adrenaline. The outer layer of the adrenal gland (also called the cortex) is responsible
for producing corticosteroids. The two hormones produced by the adrenal gland that are most commonly deficient
in a condition of Addison's disease are cortisol and aldosterone.
Cortisol, which is part of the glucocorticoid group of hormones, helps your dog's body deal with stress, aids in proper conversion of food into energy, and manages the immune system's inflammatory response. Aldosterone, which is part of the mineralocorticoid group of hormones, helps maintain proper blood pressure, as well as allowing the kidneys to keep a proper balance of sodium and potassium in your dog's body.
While Addison's disease is a condition in which there is a deficiency of corticosteroid production, Cushing's disease is the exact opposite. Dogs with Cushing's disease will have an excess of corticosteroids, usually cortisol. The treatment for Cushing's disease involves a suppression of hormone production through carefully regulated use of certain treatments. However, dogs undergoing treatment for Cushing's disease may develop Addison's disease, especially if their corticosteroid production drops dramatically from use of the Cushing's disease treatments. This may cause Addison's disease, and will require a different treatment approach.
There are two different classifications for Addison's disease, which depend largely on the underlying cause of the adrenal insufficiency. In primary Addison's disease, the adrenal insufficiency is directly caused by improper function or damage to the adrenal glands. In secondary Addison's disease, the adrenal insufficiency is not because of malfunctioning adrenal glands. Secondary Addison's disease is caused by the improper transmission of the hormone ACTH from the pituitary gland, or a reduced production of corticotropin releasing factor (CRF) by the hypothalamus. In secondary Addison's disease, the adrenal gland is still functioning normally.
With proper treatment procedures, a dog with Addison's disease can still participate in all of their normal daily activities. Even though dogs with Addison's disease will usually require medication therapy for the rest of their lives, this is a treatable disease that does not have to affect your dog's quality of life.