Cortisol Concentration in Horsehair and its Relationship to Body Location, Coat Colour, and Gender.
Authors: Lelláková Monika, Lešková Lenka, Florián Martin, Mesarčová Lýdia, Skurková Lenka, Peťková Barbara, Takáčová Daniela, Kottferová Jana
Journal: Journal of equine veterinary science
Summary
# Editorial Summary Hair cortisol analysis offers farriers, veterinarians, and coaches a non-invasive window into chronic stress levels, yet its reliability hinges on methodological consistency that many practitioners may not fully appreciate. Researchers sampled horsehair from eight distinct body locations—including chest, saddle regions, fetlocks, mane (withers and behind ears), and tail—in 31 horses, revealing statistically significant variation in cortisol concentrations depending on where samples were collected. Coat colour emerged as a critical confounding variable, with black, white, and brown hair showing meaningfully different cortisol levels, whilst animal sex had no measurable effect on results. These findings suggest that to generate valid, comparable data for stress assessment, practitioners must standardise both sampling location and hair colour when establishing baseline measurements or tracking changes over time. Without accounting for these variables, cortisol readings risk misinterpretation, potentially leading to inappropriate management decisions based on apparent stress levels that reflect sampling artefact rather than genuine physiological status.
Read the full abstract on PubMed
Practical Takeaways
- •Always sample hair from the same body location and coat color when monitoring individual horses' cortisol levels over time, as location and color significantly affect results
- •Hair cortisol testing can be used as a non-invasive chronic stress indicator, but standardized sampling protocols are essential for accurate interpretation and comparison between horses
- •Gender of the horse does not influence hair cortisol levels, so sex-based adjustments are unnecessary when evaluating stress
Key Findings
- •Cortisol concentrations in horsehair differ significantly by body location sampled (8 different areas tested)
- •Black, white, and brown hair showed statistically significant differences in cortisol concentration levels
- •No significant differences in cortisol concentrations were found between male and female horses
- •Hair color and sampling location substantially affect cortisol concentration results, requiring standardization of sampling protocol