Veterinary care includes diagnostic tests to identify the presence of Addison's disease, determine any underlying causes, and help guide subsequent treatment recommendations.Diagnosis In-depth
Certain diagnostic tests are needed to diagnose hypoadrenocorticism and exclude other diseases that may cause similar symptoms: A complete history and thorough physical examination are initially performed. Special attention is paid to abdominal palpation (eliminating foreign bodies or abdominal masses) and thoracic auscultation (listening carefully for an irregular or slow heart rhythm).
A complete blood count may show a mild anemia (low red blood cell count), or mild elevation in eosinophils and lymphocytes (certain types of white blood cells).
A biochemical profile often reveals elevations in kidney function tests, serum potassium, and serum phosphorus. Usually sodium and chloride levels in the blood are low. Occasionally serum calcium is also elevated.
A fecal test is performed to rule out the presence of intestinal parasites.
Chest X-rays may show a small heart and small blood vessels leading to the heart if the animal is collapsed, dehydrated and in shock.
Abdominal X-rays help exclude a gastrointestinal foreign body or mass as the cause, and are often normal.
An abdominal ultrasound may be needed to rule out kidney disease, other urinary tract problems, and to assess the size of the adrenal glands.
An electrocardiogram (EKG) may be recommended, and may show an abnormally slow heart rhythm, which arises with severe hyperkalemia.
Measuring blood pressure may be considered in weak or collapsed animals.
An ACTH stimulation test is a blood test that measures adrenal gland function. This test is the best means of confirming the diagnosis. It is a timed test that your veterinarian can usually perform.
Your veterinarian may recommend additional tests to exclude or diagnose other conditions. Such tests are selected on a case-by-case basis. They include the measurement of certain other circulating hormones, such as the pituitary hormones, thyroid hormones, and parathyroid hormone.
Treatment of hypoadrenocorticism must be individualized for each patient. Treatment may necessitate immediate hospitalization in those cases of extreme weakness, collapse, or shock. However, in other cases, medical management can be instituted as an outpatient. Treatments may include:
Very aggressive therapy is indicated for those cases in shock, those with severe electrolyte abnormalities, abnormal kidney function tests, high calcium levels, low blood sugar, and abnormal heart rhythms.
Intravenous fluid therapy is very important, and often involves administration of a normal saline solution to bring sodium levels back up to normal, and to lower potassium levels.
Other therapy may also be needed to lower blood potassium.
Glucocorticoids (dexamethasone, prednisone, or methylprednisolone acetate) are indicated during treatment of an acute crisis state. Depending on the individual case, they may or may not be recommended for long-term therapy.
Mineralocorticoids are started in all cases of hypoadrenocorticism. They are available in either injectable (DOCP) or oral (Florinef®) forms, and are usually required for the lifetime of the cat. DOCP (desoxycorticosterone pivalate)
Percorten-V® is an injectable medication that is administered by your veterinarian every 3 – 4 weeks, with the exact interval being established by frequent blood test monitoring.
Florinef® (fludrocortisone acetate) is an oral medication administered once or twice daily. It is the more commonly used mineralocorticoid, although it requires excellent owner compliance and is quite costly.