Preventing colic often is easier than dealing with it. But how can you tell if your horse is at risk for colicking and, thus, make necessary adjustments to his life to reduce his colic risk? A group of Brazilian researchers recently proposed that a fairly simple method, known as cortisol circadian rhythm (CCR) ratio, could be used to identify horses under chronic stress, which could indicate a higher likelihood of colic.

Rafael Faleiros, DVM, PhD, a professor at Federal University of Minas Gerais and author on the study, explained that the CCR ratio is a "simple method proposed by Dr. Robert Douglas (PhD) from BET Laboratories to assess the CCR," involving two blood samples taken eight hours apart. Cortisol, which is primarily produced by the adrenal gland, is often termed the "stress hormone" because its levels rise in response to stress in horses and other species.

"A CCR ratio below 0.30 indicates that there is an abnormal stimulus to the production of cortisol," Faleiros explained.

In the study, researchers separated 116 police horses into four groups according to their housing conditions and type of work:

  • Group 1 was stabled full-time and used for urban patrol;
  • Group 2 was stabled full-time and used for sport activities;
  • Group 3 was stabled part-time and used for urban patrol; and
  • Group 4 was kept on pasture full-time with no structured activity.

Researchers took blood samples from each horse between 6:00 and 7:00 a.m., and again eight hours later to determine the CCR ratio. Additionally, the incidence of colic among all groups was examined over th