Addison's

Looking After
Your Pets Health

590 Lark Street

Geneva, IL

630 232-8868

Hypoadrenocorticism

Hypoadrenocorticism, (Addison’s) is a disease that affects the adrenal glands of dogs, cats, ferrets and other animals. Dogs are more commonly affected than cats. The disease results in a decreased production of a hormone cortisol and/or aldosterone by the body. The decrease in production of cortisol results in a decreased ability of the body to cope with stress and a decreased ability of vessels to constrict and maintain blood pressure. A decrease in aldosterone, (mineralocorticoid) results in an inability of the kidneys and body to maintain a normal sodium and potassium electrolyte balance. Hypoadrenocorticism is usually a combination of a decrease in both hormones but also be a variation of the two. This disease is often referred to as the "great pretender" as none of the signs are specific to Addison's and therefore make it difficult to diagnose. Atypical Addison's disease (only a deficiency of Cortisol) can often be very difficult to diagnose as the general blood work will be normal and clinical signs are not specific to Addison's disease.
Signalment

·	Most dogs are younger, typically less than 7

·	Females are more commonly affected

·	Standard Poodles appear to be more commonly affected

Signs:

·	Intermittent vomiting, diarrhea or anorexia

·	Weakness or depression

·	Shock and hypovolemia

·	Slow heart rate

·	Stress intolerance

·	None of the signs are specific for Addison's disease

Diagnosis

·	General lab work

o	Often normal

o	May show signs of dehydration

o	Elevated Potassium with a decreased Sodium is classic

n	May not always be seen

o	Serum Calcium levels may be elevated (seen in about 25% of cases)

o	Increased kidney values may occur

·	ACTH Stimulation test

o	A blood sample is taken to check a baseline cortisol (hormone) level, then an injection of ACTH (another hormone that stimulates the adrenal gland) is given. A blood sample is the obtained 1-2 hours later to check for a change in cortisol levels.

o	Test for definitive diagnosis

o	Reveals minimal or no change in serum cortisol after administration of ACTH

Treatment

·	Fluid and electrolyte replacement on an emergency basis

·	Fludrocortisone is a mineralocorticoid, (aldosterone) which also has glucocorticoid activity and may be used as the sole therapy. It is an oral medication. Resistance may develop. It is difficult to dose in larger dogs.

·	DOCP (Percorten)- strictly a mineralocorticoid and must usually be given in combination with a glucocorticoid, (prednisone). It is an injection given around every 28 days or as determined by monitoring electrolytes.

·	Hydrocortisone- an inefficient therapy that should only be used alone if other therapies are not affordable.

·	Prednisone- usually used in conjunction with DOCP. Usually give orally every other day. Dose may be increased during times of stress, (i.e. company, parties, etc).

·	Medication dosages are dependant upon electrolyte levels. Thus, electrolytes (sodium and potassium) should be checked regularly upon initial diagnosis then periodically

Prognosis

Generally good if adequate control can be achieved with medication and acute hypovolemic episodes are avoided. Most pets will at some point have a relapse if close monitoring of electrolytes is not maintained.