Treatment trade-off

Surgery to remove the rare tumor behind my horse’s eye carried the risk of serious complications or worse, but if successful it would add years to his life.

Imp, my Trakehner gelding, had been a generous gift from a friend about five years ago. He was 19 then, and in addition to being a sweet and handsome guy, he was a talented and experienced upper-level dressage horse. He was also safe and sane under saddle, and his new job was to be my schoolmaster.

I moved Imp into a training barn, and all went well. He did have his quirks---he didn’t always get along with his pasturemates, he often demanded to be brought in well before his outside time was up, and he tended to have strong opinions about just about everything. But he was a dream to ride.

Then, just months later, Imp suddenly turned up head-bobbing lame. The veterinarian diagnosed a tear in his sesamoid ligament. Despite all our rehabilitative efforts, the injury would never heal enough for Imp to be brought back into even light riding. I brought him home to be a pasture horse, hoping that with enough time off, he might heal on his own. But one year stretched into several, and he never became fully sound. His strong personality simply became part of the atmosphere at the barn.

“What is wrong with his eye?” The question came from a friend who visited us in the fall of 2012. She had taken to Imp right away, loving his wavy long hair, regal bearing and quirky personality. But she’d also noticed a subtle change that, in my day-to-day care, I had missed.

I took a closer look. The inside corner of Imp’s left eye was angled downward, pulled by the skin around the eye. Thinking the skin had somehow adhered to the fascia0 below, I gently massaged the area, trying to get it to loosen.

When that didn’t help, I called my veterinarian, Katie Collier, DVM, of Fieldstone Veterinary Service in Grand Ledge, Michigan.

Wait and see

After a close examination that included x-rays, Collier confirmed that something was indeed very wrong. She explained that she saw a mass growing in the orbit (socket) behind Imp’s left eye and that it was pushing the eyeball outward, causing the skin around it to stretch.

We talked about treatment options, but none seemed reasonable or practical at that point. Trying to remove the mass would be very difficult without removing the eye, too, but Imp didn’t seem to be in any pain, so putting him through surgery that drastic didn’t seem right. We decided to just monitor the situation to see if the eye would get worse. Imp had worked hard during his life, and I was happy to focus on simply making his last years as pleasant as possible.

But as the months passed, Imp’s eye began bulging more noticeably. Michigan State University, with its large animal ophthalmology service, was only about a half hour away, and the worry that I hadn’t explored all the options nagged at me. So I made an appointment there in the spring of 2013.

Ophthalmology resident Freya Mowat, BVSc, PhD, examined Imp. She told me the mass behind his eye was most likely some type of cancer, and we discussed a variety of diagnostic options. None were appealing. A biopsy of the tumor would be difficult, given its location, and treatments to shrink it would likely have no significant impact.

Surgery to remove the mass would be painful and risky---and there was no guarantee that they could reach all of it or save the eye. If the tumor never got any worse, it might still be best to just HAPPY DAYS: Now fully recovered from surgery, Imp is enjoying his retirement.