Does My Dog Really Have Cushing’s Syndrome?

Posted on October 8th, 2014

Unfortunately, when a cortisol level is elevated, the first thing you may be told is your dog may have Cushing’s Syndrome, even if your dog’s clinical signs do not correspond to too much ACTIVE cortisol.

What is Cushing’s Syndrome?

According to WebMD, “Cushing’s Syndrome is a disease caused by long term exposure to high levels of glucocorticoid (cortisol), either manufactured by the body or given as medication.”

In the late 1930’s, Edward Cushing MD reported on pituitary tumors in patients that produced excess amounts of pituitary hormone referred to as ACTH (Adrenocorticotropic Hormone). This excess production of ACTH by the pituitary gland stimulates the zona fasciculata (middle layer adrenal cortex) to produce excessive amounts of damaging ACTIVE cortisol.

To understand the relationship between the hypothalamus-pituitary axis and the middle layer adrenal cortex, it is necessary to realize that they work with each other in a negative feedback mechanism.

When the adrenal cortisol has completed its hormonal functions in the body and is broken down by the liver and excreted by the kidneys, the reduced amount of cortisol stimulates the hypothalamus, to release its hormone referred to as CRH (Corticotrophin Releasing Hormone). The release of the hypothalamic CRH, in turn causes the pituitary gland to release its ACTH, which causes the middle layer adrenal cortex to release more regulatory cortisol.

This entire hormonal process is referred to as a negative feedback mechanism.

According to WebMD, this excess production of pituitary ACTH is the cause of 85% of Cushing’s Syndrome and the other 15% are caused by cortisol producing tumors of the adrenal glands themselves.

Within that 15%, I think Iatrogenic Cushing’s Syndrome should be included also, which comes from the over use of medical, cortisol replacements.

  • Hair loss in a symmetrical pattern
  • Dull, dry, brittle hair
  • Hyperpigmentation (Excess pigmentation of the skin)
  • Small areas of blackheads in the skin of the abdomen
  • Infertility in females and lack of ovum production
  • Infertility in males, atrophy of the testicular tissue, and a low sperm count
  • Weakness with muscle atrophy
  • Lethargy
  • Pendulous abdomen
  • Increased thirst
  • Increased urination
  • Chronic bacterial infections

Please remember, even if your dog’s cortisol levels are elevated and your dog is not showing most of these clinical signs, your dog may not have Cushing’s Syndrome. If this is the case, the middle layer adrenal cortex may be producing an elevated, defective INACTIVE cortisol that is not recognized by the hypothalamic- pituitary axis. If this is the case, the condition your dog is suffering from is Atypical Cortisol Estrogen Imbalance Syndrome (ACEIS) and not Cushing’s Syndrome.

In this instance, treating an ACEIS dog with drugs to destroy the adrenal cortex, the cortisol producing layer, could prove to be fatal!


ACEIS refers to the production of a defective, INACTIVE cortisol that can be normal or elevated, and is not Cushing’s Syndrome. Cushing’s Syndrome refers only to an elevated amount of ACTIVE cortisol.

To diagnose Cushing’s Syndrome, laboratory tests have been designed to measure cortisol levels using injectable ACTH (ACTH Stimulation Test) and dexamethasone (Dexamethasone Suppression Test). Even if these test results reflect elevated amounts of cortisol, they do not indicate whether the cortisol is ACTIVE or INACTIVE!


Cushing’s Syndrome, due to its production of elevated ACTIVE cortisol, allows the ACTIVE cortisol to cause many different disease effects, as listed above. The excess amounts of ACTH from the pituitary keep stimulating ACTIVE cortisol production from the middle layer adrenal cortex and both can more than fulfill their obligation to the negative feedback mechanism. The ACTH keeps its production going and in the negative feedback mechanism, ACTIVE cortisol will continue to be produced.

ACEIS differs from Cushing’s Syndrome in that the ACTH production continues, because the INACTIVE cortisol cannot fund the negative feedback mechanism, since the cortisol is defective and INACTIVE. This type of cortisol cannot be recognized by the hypothalamic pituitary axis.

In this instance, the defective INACTIVE cortisol cannot fulfill its obligation to fund the negative feedback to the hypothalamic-pituitary axis. Furthermore, the elevated defective, INACTIVE cortisol will still be measured with the Cushing’s Syndrome tests, but will NOT cause the clinical problems that the elevated ACTIVE cortisol does.

Since the defective, INACTIVE cortisol cannot fund the negative feedback to the hypothalamic pituitary axis, ACTH production continues. The inner layer adrenal cortex responds in a direct feed back mechanism to the hypothalamic pituitary axis, by producing excess amounts of adrenal estrogen and androgen. NOTE: This article deals only with elevated amounts of adrenal estrogen.

The elevated adrenal estrogen does the following:

  • It deregulates the immune system.
  • It causes the B-lymphocyte to no longer function to protect the body against bacteria, or make protective antibodies, including those that are hopefully produced by the use of vaccinations.
  • It causes the T-lymphocyte to no longer protect the body from viruses, molds and fungi.
  • It causes the immune system to lose recognition of self-tissue and cause autoimmunity.
  • It binds the receptor sites of T3 (triiodothyronine) and T4 (thyroxin). Note: Even though the T3 and T4 hormones measure within the normal range, because of the estrogenic thyroid block, thyroid supplementation is still indicated.
  • It causes a reduction in the B-lymphocyte production of antibodies (immunoglobulins) and when the mucous membrane antibody, referred to as immunoglobulin A (IgA), is below 58 mg/dL in a dog, malabsorption of foods, medications and nutritional supplements may occur.
  • It causes inflammation of all the cells (endothelial) that line the arteries in the body.
  • It causes elevated liver enzymes, plus a myriad of other diseases that arise from inflammation.

Please remember the amount of elevated cortisol that is present, must be identified as ACTIVE or INACTIVE. This can easily be done with a comparative endocrine, immune blood test.

The information for this blood test can be found on my website: Animal Protocol.

ACEIS, with its defective, INACTIVE elevated cortisol, is the CAUSE of allergies, autoimmunity and cancer in dogs, cats, horses and humans. NOTE: Several thousand endocrine immune blood test results indicate this.

These conditions have nothing to do with Cushing’s Syndrome and as a matter of fact, many of these conditions respond favorably when given an ACTIVE Cortisol supplement.

Please remember, even if your dog’s cortisol levels are elevated, without knowing if the cortisol is ACTIVE or INACTIVE, the value of doing an ACTH Stimulation Test or a Dexamethasone Suppression Test, is questionable.

For further information, please refer to Atypical Cortisol Estrogen Imbalance Syndrome (ACEIS).

For further information on doing the actual blood test and information on the only veterinary laboratory that can test for Total Estrogen, please go here: Laboratory Information.

Hopefully this article will help you decide if your dog really has Cushing’s Syndrome.


Dr. AL Plechner