Lab work just came back from Cornell with Sunburst (mini, 9h, 250lbs) testing ACTH at 28.1 pg/ml, down from 453 pg/ml in August. Case history has been updated. Local vet is recommending reducing Prascend dosage from 1mg to .5mg. Thoughts? In my previous thread reducing dosage was advised against, but I didn't have the lab results yet. Thank you!
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Caitlin Cobb
South Carolina 
https://ecir.groups.io/g/CaseHistory/files/Caitlin%20and%20Sunburst 
11/2020

Hi Caitlin,
That’s an amazing drop In ACTH.  A normal ACTH would generally be in the mid teens, mid way in the testing range so I would recommend keeping the pergolide dose the same as it seems to be what she needs.  However, I know that you’re concerned about her lack of appetite and weight loss and are hoping that dropping the pergolide dose would relieve that issue.  Now that you’re out of the fall rise, the more dangerous time of year, you could try playing with the dose.  If you decide to go back to 0.5 mg, be sure to test ACTH again about 3 weeks after decreasing the dose.  During that time, carefully track any changes you observe.
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Thank you, Martha. The vet was concerned we had gone "too far the other way". Thank you for the goal of teens. Is there such a thing as ACTH being too low? Secondly, if I continue to maintain her at the the 1mg will I need to retest for seasonal rise (1mg was the seasonal rise dose)?  I'm just trying to get a picture of how to manage her moving forward that keeps her the "safest". After reading all of the responses from the weight loss post, I am trying to feed her more (approved foods). I don't want to change the pergolide dosage if that is not the best thing for her. 
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Caitlin Cobb
South Carolina 
https://ecir.groups.io/g/CaseHistory/files/Caitlin%20and%20Sunburst 
11/2020

Caitlin, I probably tested to excess when I was monitoring and adjusting Logo’s pergolide doses.  If you can only manage an annual testing, I would do it in late July or early August to see if adjustments need to be made before the upcoming rise.  An additional test might be made at this time of year to see how the rise was weathered.  Generally the dosage changes would then be made based on your testing results, rather than the calendar.  Most horses, unless they are marginally PPID, do not have their pergolide doses decreased after the rise.  
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Given that she is within the normal range of 9-35 pg/ml now, although still towards the higher end of it, I would say her current dose is adequate.  If she was mine I definitely would not reduce her dose, especially because her insulin has come down with it substantially to a normal healthy level (although that could also be due to feeding safer food, too).  Martha is right in that her ACTH could be even lower.  You might find that next August you need to increase her Prascend again, it's very possible 1mg was not enough for the seasonal rise given how high it was in August and that you didn't test after getting her on 1 mg in Sept-Oct when the rise us at its peak.

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Kirsten and Shaku (IR) - 2019
Kitimat, BC, Canada
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