Veterinarians found that short-term survival rates for geriatric horses (16 to 20 years of age) undergoing surgery because of a strangulating small intestinal lesion were a little better than mature horses (4 to 15 years of age): 86 percent for geriatric patients vs. 83 percent for mature.

Other survival rates showed small differences: large intestinal strangulating lesion—78 percent geriatric vs. 70 percent mature—and large intestinal simple obstruction—80 percent geriatric vs. 97 percent mature.

There was little difference in survival rates between 16-year-old and 20-year-old horses.

It's clear that the age of the horse isn't the only factor in survival rates, but Dr. Louise Southwood, PhD, assistant professor of emergency medicine and critical care at New Bolton Center, says data like this can help horse owners make difficult choices about colic surgery later in a horse's life.

Researchers next will look at long-term postsurgical survival rates of horses 20 to 25 years old.