You are right on all counts. Thyroid meds won't cure IR but may temporarily help to jump start a sluggish thyroid if the horse is overweight and thyroid numbers are lower due to primary factors causing secondary hypothyroidism. The body will adjust for the added hormone by decreasing production over time. As Baron isn't overweight and everything else is in place don't see how adding thyroid hormone supplementation will help.
You're not alone in this dilemma. I also have one that drives me crazy with the insulin/glucose numbers always putting him in severe IR/founder risk category. Any possibility there is a PPID component to it?
Lavinia, Dante, George Too and Peanut Jan 05, RI EC Support Team