Cushing's Disease in Dogs (Canine Hyperadrenocorticism)

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Filed Under: Internal Medicine

Healthly people, dogs, cats and other animals have several sets of "ductless glands."  These glands are like small "factories", each responsible for manufacturing a unique "chemical messenger" that is packaged and then distributed by the blood throughout the body.  Examples of each glands include the thyroids, ovaries and testicles.  Their products are called "hormones," which act to increase or decrease activity of other organs or tissues.  For good health, each hormone must be produced in the amount needed.  Too much or too little of any hormone may cause illness.

The "adrenals" represent a pair of glands responsible for producing several vital hormones, including cortisone.  "Renal refers to "kidney" and "ad" means "next to."  One adrenal gland is located next to each kidney.  The condition associated with chronic excesses of cortisone is called by several names:  hypercortisolism, hyperadrenocorticism, or "Cushing's Syndrome."  About 80 years ago, Dr. Harvey Cushing is credited for being the first to describe a group of people, each ill due to chronic excesses in cortisone.  This is why some refer to the disease by using his name. 

A tumor producing  excess cortisone can develop in either adrenal gland.  This is called "adrenal tumor hypercortisolism" and is recognized in about 15 to 20% of dogs with naturally occuring Cushing's syndrome.  The majority of dogs with naturally occurring Cushing's syndrome (80-85%) have a tumor in the "pituitary" gland, located near the bottom of the brain.  The pituitary gland is also called the "master gland" because its job is to control function of other glands, including the adrenals.  Some pituitary tumors produce excessive chemical messages telling the adrenals to produce cortisone.  The result is "pituitary dependent Cushing's syndrome."  Finally, dogs being administered steriod hormones by their owners or Veterinarians may develop clinical signs which mimic naturally occurring disease and this is called "iatrogenic hypercortisolism."

More information on Cushing's syndrome provided by Vet Specialists.  Click on the below link: