Re: Sparkles, Trying to Make sense of this case ... Tick disease, IR, Laminitis
Early PPID is certainly a possibility. Its possible that the reason Sparkles responded more slowly to dietary changes than your Morgan because the dietary changes don't treat the PPID so they don't really recover until the seasonal rise has ended and then you are dealing with the damage to the hooves, which can extend the recovery period even further. But each equine is an individual and they don't all respond the same way, regardless.
The TRH stim test should be done outside of the seasonal rise. The seasonal rise starts with the summer solstice, peaks with the fall equinox, then officially ends by the winter solstice, although the rise comes on slowly so effects on ACTH normally don't occur until August. There is no reason not to do the TRH Stim test now or early this spring. We do recommend retesting baseline ACTH (not TRH Stim) in late summer to see if ACTH is climbing too fast and medication dosages need to be increased to control ACTH through the fall rise. Once diagnosed with PPID, these horses do best if ACTH is kept in the normal range throughout the seasonal rise, and normal for these horses is in the high teens to low 20s.
Another way to diagnose early PPID in horses with normal ACTH is to test baseline (not TRH Stim) ACTH at the peak of the rise; it will be abnormal then. My horse had all the physical signs of PPID but normal ACTH, except at the peak of the seasonal rise.
It sounds like you are doing a lot to help your metabolichorses, and I love your track system, too. If you can put up some additional electric strings lower down, or a physical barrier like 4" mesh livestock fencing, that should stop Sparkles from getting through the fence to eat. I added a lower electric line 6" above the ground and a physical barrier when I noticed my horse was still able to get grass from under the bottom electric string, which was 12" above the ground. They will do almost anything for that grass!
Kirsten and Shaku (IR + PPID) - 2019
Kitimat, BC, Canada
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