Adrenal Cortical Atrophy
The adrenals are two crescent-shaped glands that sit on top of each kidney. The adrenal glands secrete hormones directly into the bloodstream. They are divided anatomically and functionally into two main parts: the medulla (middle) and the cortex (rind) (Clayman 1989). Additionally, each division of an adrenal gland consists of internal layers that produce different hormones. Constant stress and poor nutrition can weaken the adrenal glands. When stress continues over prolonged periods of time, the adrenal glands can deplete the body's hormonal and energy reserves, and the glands may either shrink in size or hypertrophy (enlarge).
Adrenal cortical atrophy is destruction of the outer layer of the adrenal
glands, small glands situated on the kidneys. This results in deficient
production of hormones called mineralocorticoids and glucocorticoids.
Addison's disease or primary adrenocortical deficiency results from destruction of the adrenal cortex. Glucocorticoid, mineralocorticoid and sex steroid production are all reduced.
The most common symptoms of this disorder are lethargy, vomiting, anorexia and weakness. Other signs such as diarrhoea, weight loss, increased thirst and increased urination may also be evident. The destruction of the adrenal glands is a gradual process. Initially partial destruction of the adrenal cortex produces symptoms that are only obvious during stressful situations such as boarding, travel or surgery. As the adrenal glands are progressively destroyed, the symptoms are evident even in non-stressful situations, and the majority of dogs have chronic problems that may have been present for up to one year. Dogs most at risk are young to middle aged female dogs and castrated male dogs.[1]
CAUSES In addition to autoimmunity and tuberculosis, infectious fungal diseases (coccidioidomycosis and histoplasmosis) or viral infections (cytomegalovirus and HIV) have been reported to be responsible for chronic adrenal damage leading to clinical Adrenocortical insufficiency (Addison's Disease). Primary tumors or metastases from malignant tumors elsewhere (lung, breast, stomach, lymphomas, and melanoma) are known to cause chronic adrenal insufficiency.
Adrenal cortical atrophy has been reported to result from alpha-particle irradiation to the lymphatic system.[2]
If treated, patients with this diseases can have a normal lifespan.
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