During the seasonal rise, a PPID horse will have much more of an elevation in ACTH than a normal horse. An ACTH of 28 in a horse during the seasonal rise (assuming he is not on pergolide) pretty much rules out Cushings; while an ACTH during May or June, when it should be lowest, puts that horse squarely into the "Grey area; re-test during seasonal rise" category.
Since it looks like Ulysses had a mid-August ACTH of 28, it also looks like he is not Cushings. My idea of using the TRH stim test was unnecessary because of this August result.
Therefore, he shouldn't be on pergolide; it is possible that the improvement of signs after the introduction of the pergolide in October, and raising it .2 mg in January, is a coincidence/red herring. Ulysses has a lot of confounding factors, between the CPL and various allergies.
IF he was truly PPID, then under the circumstances I would recommend getting ACTH into the mid-teens if possible. However, it looks like I was running down the wrong trail!
Regarding dose: as Dr. Kellon says, the correct dose of pergolide is the one that controls the ACTH.
---In EquineCushings@..., <kathbrink@...> wrote :
Can you please expand on the significance of the ACTH of 28 during the seasonal rise for Ulysses.
Would you still recommend getting his ACTH in the mid teens?
If a 0.8 mg dose of Pergolide is probably insignificant for a 1750# Draft should he even be on pergolide or should he be on a higher dose?!
I am not connecting the dots. :-)