Addison Disease (Hypoadrenocorticism), Urination Problems

Addison disease is fairly rare, and most cases are the result of an atrophy of the adrenal gland. Addison disease is the opposite from Cushing's disease. Cortisol production is deficient instead of overabundant. In Addison disease, cortisol production is not the only problem, however, because other adrenal hormones will be insufficiently produced. Addison disease can be fatal, because dogs can't survive without adrenal hormones.

Two iatrogenic ("doctor-caused") forms of Addison disease may occur in dogs with adrenal damage from having been over-treated with certain corticosteroids for inflammatory conditions. Some of these patients recover with time if the medicine is withdrawn, but in others, the damage to the adrenals is permanent.

The other form or iatrogenic Addison disease can occur in Cushing disease patients overtreated with drugs used to control cortisol overproduction. In this form of Addison disease, damage to the adrenals is permanent.

Signs of Addison Disease

Depression is often the first sign of Addison disease. The dog may be weak, have little energy, and become anemic. Appetite may be diminished and the dog may loose weight. It may also vomit and have loose stools. Some dogs with Addison disease drink and urinate a lot. An important clinical sign of Addison disease is that the signs can come and go.

Treatment of Addison Disease

Diagnosis of Addison disease involves blood tests to check levels of the chemicals produces by different organs. Because this disease is potentially life-threatening, treatment may begin before test results confirm the diagnosis.

Dogs with this disease may have very low blood pressure and abnormal electrolytes levels. These are serious signs that can cause shock and death. Both these problems can be helped by increasing fluid intake. Re-hydration therapy is started immediately, even before beginning to treat the adrenal problem.

To treat Addison disease, the dog is administered the hormones it is unable to produce. Cortisone is the easiest to replace; low doses of the drug prednisone are used for this. The adrenally produced mineral corticoids are more difficult to replace. These hormones normally regulate production of electrolytes, without which the body is unable to function. The medication for this can be given orally on a daily basis, injected monthly or implanted under the skin in pellet form every ten months. A dog must be retested periodically to assure proper dosage.

Use of Cortisol

Cortisol is the principal glucocorticoid secreted by the adrenal cortex which helps metabolize nutrients, mediate physiologic stress, and regulate the immune system. Cortisol levels normally rise during the early morning hours and peak around 8 a.m., and then decline to very low levels in the evening and during the early phase of sleep. Intense heat or cold, infection, trauma, exercise, obesity and debilitating diseases influence cortisol production.

Adrenal Glands

The adrenal glands secrete mineralocorticoids (primarily aldosterone) to maintain sodium and water balance; glucocorticoids (primarily cortisol) to regulate carbohydrate, fat, and protein metabolism; sex steroids (androgens and estrogen); and catecholamines (mainly epinephrine, norepinephrine, and dopamine) to regulate reactions to stress. The adrenal cortex secretes mineralocorticoids, glucocorticoids, and sex steroids.