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Hypoadrenocortcocism (Addison's Disease)

General Information

Addison's disease is a disorder of the adrenal glands in which adrenal hormone production is insufficient. The condition may result from damage to the glands by in-fection, cancer or drugs, or the cause may not be known. Pituitary gland disease may also cause adrenal insufficiency.

Insufficient adrenal hormones can upset the body's conservation of sodium (salt), reduce circulating blood volume, impair heart and kidney function, damage the heart muscle, and cause faulty sugar and fat metabolism. Decreased tolerance of stress is the primary characteristic of Addison's disease, and affected pets are often presented in a shock-like state of collapse called an Addisonian crisis.

Extensive blood and adrenal function tests are necessary to properly diagnose and plan treatment for Addison's disease.

Important Points in Treatment

1. Initial treatment of adrenal insufficiency usually is done in the hospital, due to the need for intravenous fluids and medications and frequent laboratory tests. Your pet will be released as soon as the disorder can be treated effectively at home. Lifetime treatment is usually needed. This treatment may consist of either daily medications to replace the missing natural hormones or injections that may be given monthly. Which treatment works better depends on the individual patient.

2. Give all the medication as directed. Call the doctor if you cannot give any medication prescribed.

3. Activity: Your pet should be kept quiet during the initial recovery period due to its inability to react properly to stress. Once your pet's condition is stable, activity can be gradually increased to normal.

4. Provide access to clean, fresh drinking water at all times.

5. Ordinarily no special diet is required, but some pets require salt supplementation. Your doctor will advise you if this is necessary for your pet.


Notify the Doctor if Any of the Following Occur:

* Your pet vomits or has diarrhea.

* Your pet seems overly thirsty and urinates frequently or has "accidents."

* Your pet has periods of well-being interrupted by brief episodes of illness, weakness or depression.

* Your pet is depressed.

Question and Answer

Hypoadrenocorticism (Addison's Disease)

Understanding Your Pet's Medical Diagnosis

What is hypoadrenocorticism?

Hypoadrenocorticism is an endocrine (hormonal) disorder caused by deficient production of adrenal hormones. Primary hypoadrenocorticism is caused by disease or injury to the adrenal glands that leads to deficiencies in the two hormones, cortisol and aldosterone. Secondary hypoadrenocorticism is caused by administration of steroids, or by pituitary gland disease that causes reduced production of adrenal gland hormones. Hypoadrenocorticism is uncommon to rare in dogs and extremely rare in cats. Another name for hypoadrenocorticism is "Addison's disease."

What causes hypoadrenocorticism?

The causes of primary hypoadrenocorticism include immune-mediated disease (where the body's immune system attacks its own adrenal glands), excessive response or overdose of drugs used to treat hyperadrenocorticism, granulomatous disease (usually associated with chronic inflammation or infections), and cancer. The causes of secondary hypoadrenocorticism include the discontinuation of long-term therapy with steroids and a pituitary tumor or damage to the pituitary gland.

What are the signs of hypoadrenocorticism?

The signs of hypoadrenocorticism vary from mild to severe and life threatening. Signs in affected dogs may include lethargy, poor appetite, vomiting, diarrhea, weight loss, shaking, excessive thirst, and excessive urine production. Severely affected dogs may collapse, have weak pulses, and may go into shock. These cases are in "addisonian crisis," a life-threatening condition that requires emergency veterinary attention. Signs in cats may include lethargy, poor appetite, vomiting, excessive thirst, excessive urine production, and weight loss.

How is hypoadrenocorticism diagnosed?

On physical examination, the veterinarian may find that the dog is depressed. The dog may appear weak, be dehydrated, and have other signs suggestive of hypoadrenocorticism. Cats may be dehydrated, weak, and have slow or weak pulses. These signs and physical findings are seen in animals with other common medical disorders so that hypoadrenocorticism is difficult to diagnose by physical examination alone. Other tests are used to diagnose hypoadrenocorticism. Complete blood counts (CBCs), blood chemistries, and urinalysis are part of the work- up. The results of these tests can suggest the diagnosis of hypoadrenocorticism. Radiographs (X-rays) and electrocardiography (EKG or ECG, an electrical analysis of the heart) may be helpful. A special blood test, the adrenocorticotrophin (ACTH) stimulation test, provides the definitive diagnosis. If an undetectable-to-low blood cortisol level is present, and it fails to increase after administration of synthetic ACTH hormone, the adrenal glands are not functioning normally indicating that the pet does have hypoadrenocorticism.

How is hypoadrenocorticism treated?

The treatment for hypoadrenocorticism will vary depending on the severity of the disease. Acutely ill animals (in addisonian crisis) require emergency veterinary medical attention and intensive treatment. These animals need intravenous (through the vein) fluids to treat low blood volume or shock. The depleted adrenal gland hormones must be replaced quickly. Once stabilized, the animal is treated similarly to the chronic hypoadrenocorticism patient. Chronic primary hypoadrenocorticism is treated with hormone replacement, usually by injections. Lifelong administration of medication may be required. Animals must be monitored with blood tests to assess proper dosages of medications and response to treatment. Medication dosages may need to be adjusted if the animal travels, is hospitalized, or is having surgery. Such stresses can affect the animal with hypoadrenocorticism adversely.

What is the prognosis for animals with hypoadrenocorticism?

The majority of pets with hypoadrenocorticism have a good to excellent prognosis (outcome) after they have been stabilized and treated properly. However, animals with hypoadrenocorticism caused by cancer, especially cancers that have spread, or granulomatous disease have poor outcomes

The information on this page was obtained from the site www.vetmedcenter.com