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BBVA Buzzards Bay Veterinary Associates 230 Main Street * Buzzards Bay, MA 02532 * Tel: 508-759-2521 * Fax: 508-759-6782 Hypoadrenocorticism (Addison’s disease)
What is Addison’s disease? Addison’s disease is caused by the decreased production of the adrenal gland hormones. The adrenal gland is located just above each kidney, it is responsible for secreting the hormones for the “fight or flight” response. These adrenal hormones are in charge of regulating “stress” (Glucocorticoids) and electrolytes balance (Mineralocorticoids) in the body. If the glands function is impaired, pets do not respond well to "stressful situations" such as disease, trips to the groomer, visits to the veterinarian, or even day care. This disease can cause a life threatening “Addisonian crisis” wherein some of the body’s electrolyte levels become unbalanced to a life threatening level. Addison’s disease almost always affects dogs, but it has been described in the cat as an extremely rare circumstance.
Which pets can are normally affected and what are the most common clinical signs? Addison’s is most commonly seen in middle aged female dogs (4-5 years of age) or in patients that are being treated for Cushing’s disease. Clinical signs can range from depression, lethargy, vomiting and diarrhea to shock, bradycardia (low heart rate) and abnormal heart rhythm. Depression and lethargy are usually caused by mild to moderate dehydration and electrolyte imbalances. Pets can also present in what is known as the “Addisonian crisis.” These pets usually present in shock due to severe dehydration, plus bradycardia and arrhythmias due to elevated Potassium (electrolyte) levels. If the latter is not addressed immediately, the pet might not survive the episode.
Seizures are sometimes seen because of the inability to regulate blood sugar levels in times of stress (when consumption is high). Addison's disease can also cause the esophagus (tube from the mouth to the stomach) to function improperly. These pets will present with a history of regurgitating (vomiting undigested food) and possibly fever or respiratory abnormalities from aspiration pneumonia (secondary to inhaling food particles into the lungs). How is Addison’s disease diagnosed? The diagnosis of Addison's disease is made based on clinical signs, response to intravenous fluid therapy, and the results of some specific blood tests.
The confirmatory blood test to diagnose Addison's disease is called the ACTH stimulation test. This is a special two part timed blood test. Some Glucocorticoids (steroids) interfere with this test, so your doctor might need to wait up to 2 days before he/she could use this test to diagnose the disease if steroids had been used for the treatment the pet’s presenting clinical signs. Alternately, she may recommend testing immediately if she suspects your pet is having an Addisionian crisis.
How is Addison’s disease treated? Treatment is for life. The most common modes of treatment are pills (Fludrocortisone- Florinef®), or injection (DOCP- Percorten- V®). The goal of both these treatments is to keep the patients electrolyte levels within normal levels for proper organ function. Electrolytes should be tested regularly while patients treatment dose and frequency is adjusted. The usual interval for the injection is 25-30 days, while pills have to be given once to twice per day. The cost is similar for both pills and injection. We recommend that the injection be used whenever possible as just one missed dose of the pill can cause an “Addisonian crisis” and land your dog in the hospital for intensive care.
In most patients a physiological (low) dose of Glucocorticoids is added to their mineralocorticoid (electrolyte) treatment. The most common treatment is a low dose of Prednisone. Sometimes this dose needs to be increased in times of "stress" such as when the animal becomes ill, visits the groomer, goes on a long car trip, or visits the veterinary clinic.
For more information, refer to the following websites:
This handout was adapted from the Veterinary Partner website. Home | Feedback | Dr. Fox | Directions & Hours | Employment | Client Handouts | Specialty Practice
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