The gold standard of testing used to be called the Dex Suppression Test, which involved administering a dose of corticosteroids (similar to cortisol) and measuring whether or not the body's natural production of these hormones was decreased. However with new testing methods available, this test is falling out of favor with most veterinarians.
The two tests used most commonly today are baseline ACTH and the TRH Stimulation test. Both tests involved measuring the level of ACTH in the blood with some differences as to how the test is performed.
Baseline ACTH testing simply involves pulling a blood sample and sending it out for testing, no additional steps for preparation are needed. The downside to this test is that results can be affected by the season. Normal horses can have an increased level of ACTH production during the Fall, so it can be hard to differentiate the normal from the abnormal during this time.
The TRH [Thyrotropin Releasing Hormone] Stimulation Test is not as greatly affected by the seasons, and accurate reference values have been established for different times of the year. The downside of this test is that it requires an injection of TRH with blood samples taken before and after injection. This test will normally carry a slightly higher cost as well due to the TRH compound and second sample testing.
Check back next week for another question about PPID!
No comments:
Post a Comment