Every horse owner wants to avoid the dreaded "C" word, and although it sometimes is unavoidable, there are some steps owners can take to prevent colic. Housing horses in pastures rather than stalls, for example, could reduce the likelihood of a horse developing colic. According to the results of a recent study performed by a group of British researchers, there is a decrease in stall-kept horses’ intestinal motility (or movement of digesta) as compared to pasture-kept horses, which could help explain the higher risk of colic seen with stabled animals.

The research team, led by Sarah Freeman, BVetMed, PhD, CertVA, Cert VR, CertES, Dipl. ECVS, MRCVS, associate professor of Veterinary Surgery at the University of Nottingham School of Veterinary Medicine and Science, in Leicestershire, used ultrasonography to assess the frequency of large intestinal contractions (and thus, the amount of intestinal motility) in two groups of eight horses (no recent history of gastrointestinal disease) used for equitation training at the Defence Animal Centre in Melton Mowbray, UK.

The first group was stabled throughout the study period, which was comprised of two monitoring phases. They were fed hay and concentrate twice daily and had constant access to fresh water. Horses in this group were exercised lightly for 60-90 minutes daily. These horses remained in the same routine throughout both monitoring phases.

The second group was kept on pasture 24 hours a day with constant access to fresh water for the first part of the monitoring phase. They received no formal exercise or supplemental concentrates while at pasture. For the second monitoring phase, horses in this group were transferred to the stabled regime, identical to the first group. They were given a two-week acclimatization period between being turned out and stall kept.

Researchers used ultrasonography to examine two horses from each study group twice daily for two consecutive days during each monitoring period to evaluate the frequency of contractions within several parts of the large intestine.

Study results showed a measurable difference in large intestinal motility between the two groups of horses.

"The frequency of contractions of all intestinal regions collectively was significantly lower when horses were stabled compared to the pasture regime, but this effect was greatest in a region of the colon where impactions commonly occur," Freeman said in the study.

The team noted that there are several factors that differ between stable and pasture management, including feed type, feeding intervals, and activity levels.

"Any, or a combination, of these could contribute to the lower intestinal motility of stabled horses, and this will require further study," Freeman relayed. "But now that we know that stabled horses have reduced motility, we can look at measures to try and improve this and reduce their risk of colic."

The study, "Investigation of the effect of pasture and stable management on large intestinal motility in the horse, measured using transcutaneous ultrasonography," was published in August’s issue of the Equine Veterinary Journal and can be viewed online.