Assessing Stress in Horses: Fecal Cortisol LevelsBy Kentucky Equine Research Staff · October 11, 2017
Measuring a horse’s cortisol levels in certain situations, such as competition or transport, helps identify stress and serves as a useful tool for improving equine welfare. Problem is, cortisol levels aren’t always elevated in chronically stressed horses. Some studies reported lower, higher, or normal cortisol level when horses were subjected to various stressors over a prolonged period of time.
“In response to persistently stressful situations, horses often display certain behaviors confirming their compromised welfare. Examples include the development of stereotypic behavior, aggression, and postural changes, such as ear position,” explained Kathleen Crandell, Ph.D., a nutritionist for Kentucky Equine Research (KER).
Examples of chronically stressful situations include:
- Exercise restriction or confinement;
- Extreme work, especially beyond a horse’s fitness level;
- Lack of social interactions due to individual housing;
- Social conflicts by being paired with unsuitable herdmates; and
- Chronic pain due to musculoskeletal causes or chronic illness.
Recognizing the importance of measuring equine stress, and therefore welfare, one research group sought to improve understanding of chronic stress on horses. Using horses from three riding barns, the researchers measured cortisol levels in both fecal and blood samples.
“Horses with compromised welfare consistently had lower fecal and blood levels of cortisol. The fecal and blood cortisol tests therefore appear to be an appropriate tool to help assess, monitor, and improve equine welfare,” shared Crandell.
*Pawluski, J., P. Jego, S. Henry, et al. 2017. Low plasma cortisol and fecal cortisol metabolite measures as indicators of compromised welfare in domestic horses (Equus caballus). PLoS One. 12(9):e0182257.