You & Your Pet by Dr. Wise

Rhode Island Veterinary Medical Association 11 South Angell Street #347 · Providence, RI 02906 (877) 521-0103 (866) 277-0238 Toll-Free ·Fax

My dog Shane recently had his annual physical exam.  My veterinarian said that the blood and urine tests indicate that Shane may have Cushing's Disease.  What is it and how could my dog have gotten it?

First, let me commend you for having blood work and urine testing done when Shane has his annual physical.  Yearly checkups on blood counts, serum chemistry values, and urine can give an early warning about a potential problem so it can be treated before it becomes serious.  This is exactly what your veterinarian may have found in Shane's blood work.

Cushing's Disease, also known as hyperadrenocorticism, is a condition where the body is getting too much cortical - a type of steroid hormone.   Steroids can be given by injection, orally or overproduced naturally.  Too much cortisol is bad for the body.  Damage can occur to the liver, kidneys, skin and cartilage in the joints, just to name a few.  If your dog is overproducing his own cortisol, either the pituitary gland or adrenal gland is not functioning correctly.  The pituitary gland is located at the base of the brain and is responsible for many different hormonal functions.  One function is to 'tell' the adrenal gland (located near the kidneys) to produce cortisol.  Cushing's Disease occurs when either the pituitary gland is 'telling' the adrenal glands to produce too much cortisol or the adrenal glands are overproducing cortisol despite what the pituitary gland is 'saying".  

In dogs with Cushing's Disease, about 85% have a malfunctioning pituitary gland and about 15% have overproducing adrenal glands.  When the pituitary gland is responsible, a benign (non-cancerous) tumor on one of the two glands is the culprit in about half the cases.  In the other half, the cause is a cancerous tumor on the gland.  There are further tests that can be done if your veterinarian suspects Cushing's Disease.  They will determine if your dog has the disease and what form it is in.

Treatment will range from chemotherapy to surgery, depending on the location of the tumor.  Likewise, the prognosis for Shane depends on the type and location of the tumor, but Cushing's Disease may shorten a dog's life.  People can get Cushing's Disease too, but there is absolutely no danger of a dog with the disease spreading it to a person, or even to another dog.  The disease is not contagious.

This information, prepared as a public service by the Rhode Island Veterinary Medical Association, answers problems Rhode Island veterinarians currently are seeing in their practices, as well as new developments in animal care.