Canis ISSN: 2398-2942

Low-dose dexamethasone suppression test

Synonym(s): LDDST

Contributor(s): David Bruyette

Overview

  • Administration of exogenous glucocorticoid (dexamethasone) suppresses hypothalamic-pituitary axis Hypothalamic-pituitary-thyroid axis diagram.
  • Natural cortisol levels are suppressed for 78 hours in normal animal.
  • Dogs with hyperadrenocorticism show breakthrough of suppression by 8 hours.

Sampling

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Tests

Availability

  • Widely available at commercial laboratories.

Validity

Sensitivity

  • Diagnostic in all ADH cases (more reliable than ACTH stimulation test in confirming hyperadrenocorticism).
  • Diagnostic in 90-95% of PDH cases.

Specificity

  • More affected by non-adrenal disease than the ACTH stimulation test.
    Do not perform adrenal function tests in ill animals

Technician (extrinsic) limitations

  • Must be able to give intravenous injection and collect samples without stressing animal.

Result Data

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Further Reading

Publications

Refereed papers

  • Recent references from VetMed Resource and PubMed.
  • Vaessen M M A R, Kooistra H S, Mol J A & Rijnberk A (2004) Urinary corticoid:creatinine ratios in healthy pet dogs after oral low-dose dexamethasone suppression testsVet Rec 155, 518-521.
  • Feldman E C, Nelson R W, Feldman M S (1996) Use of low- and high-dose dexamethasone suppression tests for distinguishing PDH from ADH in dogs. JAVMA 209, 772-775.
  • Chauvet A E, Feldman E C, Kass P H (1995) Effects of phenobarbital administration on results of serum biochemical analyses and adrenocortical function tests in epileptic dogs. JAVMA 207, 1305-1307.
  • Kaplan A J, Peterson M E, Kemppainen R J (1995 )Effects of disease on the results of diagnostic tests for use in detecting hyperadrenocorticism in dogs. JAVMA 207, 445-451.

Other sources of information

  • Most commercial laboratories will provide information on test and interpretation of data.


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