Suppose your horse tears a ligament while romping in the pasture and the veterinarian orders stall rest. You’d worry about his injury, of course—but you also should worry about his gut. Changes in management, such as a switch from pasture freedom to stable confinement, increase the risk of impaction colic. A new study sheds light on why that’s so.
The research was led by Sarah Freeman, BVetMed, PhD, an associate professor of veterinary surgery at the University of Nottingham School of Veterinary Medicine and Science in England. Dr. Freeman is involved in a number of colic studies as well as a nationwide British colic survey. Results of the survey will be presented in July at the 11th Equine Colic Research Symposium, hosted by the British Equine Veterinary Association.
In this study, Dr. Freeman and her colleagues followed a group of seven horses as they were moved from pasture to stable. The horses were monitored 24 hours a day while they were at pasture, where they were free to move around at will, and for 14 days after they were brought into the barn, where they were stalled except during light, controlled exercise.
The horses drank nearly twice as much water in the stable as they did in the pasture, but they produced significantly less and much drier manure after the move. “There was both slowing down of gut motility and drying out of gut contents,” Dr. Freeman says. Just drinking more water apparently wasn’t enough to compensate for the change from moisture-rich grass to dry forage and the new restrictions on exercise.
While the link between colic and a sudden shift to stabling has long been recognized, the reasons haven’t been clear. This study is significant because it sheds light on how the change affects the gut. Impaction colic develops when feed dries and accumulates in the intestines, causing a blockage. When a horse moves from pasture to stable, slower gut motility and drier gut contents may make this more likely. “This is the first study to look at these changes in normal horses, and we hope that the results will help vets and horse owners modify management to reduce these problems,” Dr. Freeman says.
“The changes in function were rapid and marked and were most significant during the first five days after the change in management. We think this represents the high-risk period for colic,” she notes. There are many situations that might put a horse in this high-risk window—not just injury but perhaps a move to a new barn, temporary stabling at a competition or harsh weather conditions that prevent turnout.