Still a bit high insulin level for Scooter

Rhonda Turley

I had Scooter tested in November 11,2021 and his insulin level was sky high(1435).  Back up to earlier in the late summer he was on a mixture of straw and grass hay.  My vet had recommended this and it seemed worth a try and the result was the high insulin level.  I immediately got his diet changed (he lives in a large boarding stable) to no straw and timothy grass hay and his insulin/glucose/ACTH levels have gone down but his insulin level is a tiny bit high at 367 (should be under 300).  Is this a concern?
I also had Scooter checked for allergies at the same time.  Do allergies affect his ACTH/Glucose/Insulin levels?
His case history has been posted.
Otherwise he is very healthy and back in dressage  training and is getting fitter.
Rhonda Turley
Brampton, Ontario
April 2020
Scooter and Rhonda


Hi Rhonda,

You’re not the only one to learn the hard way that the s/s of straw is not as low as you might guess.  It seems counterintuitive but it’s good to be aware.

I’m not aware of allergies causing ACTH to be elevated but allergies can be more problematic in horses with PPID that isn’t well controlled.  Your ACTH level is right where it should be but, unfortunately, that doesn’t always tell the entire story.  You could try increasing his pergolide to see if it helps with his allergies and brings his insulin down.  There’s no harm in increasing it and then bringing it back down if you don’t find it helpful.  Keep in mind that cold temps can cause elevated insulin.  You state that it was 2°C which isn’t too far below the 40°F I think I’ve seen suggested as a dividing point.  However, we advocate for striving to achieve an insulin value midway in the range, which would be 150 +, depending on the lower value of the reference range.


Martha in Vermont
ECIR Group Primary Response
July 2012 
Logo (dec. 7/20/19), Tobit(EC) and Pumpkin, Handy and Silver (EC/IR)

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