Adrenal gland tests

Question 1

Main screening tests for adrenal hypersecretion

Answer 1

-Urine cortisol: creatinine ratio
-Low dose dexamethasone suppression test
-ACTH stimulation test

Question 2

Tests to distinguish PDH and FAN

Answer 2

-Endogenous ACTH
-High dose dexamethasone suppression test

Question 3

Urine Cortisol: Crt ratio

Answer 3

Used in dogs
If WRI no hyperadrenocorticism but if increased it may or may not have it (many false positives)

Question 4

Endogenous ACTH

Answer 4

Usually measure in horses
References depend on the lab
Increased concentration supports pituitary adenoma or hyperplasia

Question 5

Low dose dex test

Answer 5

Can differentiate and screen
Measure cortisol then give a low dose of Dex and measure the post blood cortisol after 4-8hrs

Question 6

Results of LDDST

Answer 6

Lack of suppression after 8hrs consistent with hyperadrenocorticism either from PDH or FAN
-If there was some suppression at 4hrs it is most likely PDH though

Question 7

High dose dex test

Answer 7

Only used as a differentiating test after definitive diagnosis of hyperadrenocorticism
Same concept as LDDST

Question 8

Results of HDDST

Answer 8

Suppression at 4 and or 8 hours consistent with PDH
No suppression at 4 or 8 could be either

Question 9

ACTH stimulation test

Answer 9

Measure cortisol-> give ACTH-> measure 1 or 2hr sample for cortisol

Question 10

Results of ACTH stimulation test

Answer 10

WRI-> healthy
Exaggerated increase-> hyperadrenocorticism
Inadequate response-> hypoadrenocorticism

Question 11

Tests for horses

Answer 11

19hr Dex suppression test and ACTH stimulation