Hyperadrenocorticism (Cushing's Syndrome) in Dogs - Page 5

My Pet: FREE Tools to Care for Your Pet and Connect with Others

Over 10,000 Vet Approved Articles Search All Articles

Hyperadrenocorticism (Cushing's Syndrome) in Dogs

By: Dr. Douglas Brum

Read By: Pet Lovers
Email To A Friend Print
Tests used to differentiate pituitary- and adrenal-dependent hyperadrenocorticism include:

  • High dose dexamethasone suppression test. This works on the same principle as the low dose dexamethasone suppression test, but a higher dose of dexamethasone is used. The higher dose usually causes suppression of blood cortisol concentration in dogs with pituitary-dependent hyperadrenocorticism but not in those with adrenal-dependent disease.

  • Blood ACTH concentration. This test reliably differentiates pituitary- and adrenal-dependent disease, but it is technically difficult to perform. The blood sample must be handled very carefully and sent to a special laboratory to insure accurate results. A low blood concentration of ACTH indicates the presence of an adrenal tumor whereas a normal or high blood concentration of ACTH suggests a pituitary tumor.

  • Occasionally, the low dose dexamethasone suppression test can differentiate pituitary- and adrenal-dependent causes of Cushing's syndrome. When adequate suppression is observed in the 4-hour sample, but not in the 8-hour sample ("escape"), pituitary-dependent disease should be suspected. Patients with adrenal-dependent disease (adrenal tumors) do not "escape" after suppression.

  • Presence of one large and one small or normal-sized adrenal gland on abdominal ultrasonography suggests adrenal-dependent disease whereas presence of two large adrenal glands suggests pituitary-dependent disease.

  • If the tests described above do not allow clear differentiation of pituitary- and adrenal-dependent disease, CT (computerized tomography) or MRI (magnetic resonance imaging) scanning of the brain to look for a pituitary tumor or abdomen to look for an adrenal tumor may be required. These specialized tests require referral to a specialty center.

  • Comment & Share
    Email To A Friend Print
    Keep reading! This article has multiple pages.

    Dog Photos Enjoy hundreds of beautiful dog photos Let's Be Friends Follow Us On Facebook Follow Us On twitter


    Email to a Friend

    Article to eMail
    Hyperadrenocorticism (Cushing's Syndrome) in Dogs

    My Pet
    Coming Soon

    Tools to Care for Your Pet and
    Connect with Others!

    Be the First to Know.
    Notify Me