ET recovered well with help from his veterinarians. | Photo: Courtesy Nettie Liburt

I was working when the barn manager called around 8:30 in the morning on Memorial Day 2016 to tell me that ET’s right eye was swollen shut.

My 16-year-old Appendix gelding has a propensity for getting into trouble, so this wasn’t the first time I’d made an emergency call to the vet. I hurried to the barn and met Dr. Cathe Montesano, of Montesano and Tallarico, DVM, LLP, in Smithtown, New York. After an examination, however, she gave me the most serious eye-related diagnosis I’d received: “ET has glaucoma.”

Come again? He was fine yesterday. How did this