Addison's Disease is a deficiency of cortisol (a glucocorticoid) and/or aldosterone (a mineralocorticoid). The deficiency can be caused by faulty brain (pituitary) signals to the adrenal glands or by faulty adrenal glands. Cortisol and aldosterone deficiencies cause the levels of sodium and potassium to be abnormal.
Both dogs and cats develop Addison's disease, and the following breeds have a higher incidence than normal of canine Addison's Disease:
Addison's disease can be fatal. The adrenal hormones (cortisol and aldosterone) that are diminished with Addison's Disease are necessary for maintaining normal health, including blood pressure, kidney filtration, and a strong heartbeat. Without cortisol and aldosterone, your pet will be weak and may vomit. Their heart won't beat normally; they can shake, and become dehydrated. If your pet is not treated with fluids and cortisol, he or she may die.