Hi Kate,
 I have 2 one eyed Arabians. My mare is 23, lost her eye at 14, and diagnosed with PPID/IR at 17. Thankfully, with controlled diet and exercise, she is well controlled. My gelding is 16, lost his eye before he was a year old, and shows absolutely no signs or symptoms of PPID or IR. Granted I live in the southeast US, but we have almost as many rainy days as Seattle. I doubt your horse's missing eye has anything to do with his symptoms.

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Valerie and Matera
Aug 2018
Athens, GA, USA
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