Validation of a Commercial ELISA Kit for Non-Invasive Measurement of Biologically Relevant Changes in Equine Cortisol Concentrations.
Authors: Share Elizabeth R, Mastellar Sara L, Suagee-Bedore Jessica K, Eastridge Maurice L
Journal: Animals : an open access journal from MDPI
Summary
# Editorial Summary Researchers validated a commercial ELISA kit for measuring cortisol in equine blood and faecal samples, addressing a practical need for reliable, cost-effective stress assessment tools in equine practice. Eight horses underwent a standardised 15-minute transport stressor whilst blood and faecal samples were collected before and after the event; the kit underwent rigorous analytical validation testing including parallelism, accuracy and precision assessments. Plasma cortisol rose sharply immediately post-transport (254.5 versus 142.8 nmol/L baseline), whilst faecal cortisol metabolites showed a delayed but measurable increase 24 hours later (10.8 versus 7.4 ng/g baseline), demonstrating the kit's sensitivity to biologically meaningful changes. The Arbor Assays DetectX® kit proved both reliable and economical, offering equine professionals a validated option for non-invasive stress monitoring that avoids the confounding factors of blood sampling (which itself elevates cortisol) and the diurnal rhythm variability seen in plasma measurements. For farriers, vets and coaches managing equine welfare, this provides a practical tool for objectively quantifying stress responses to handling, transport, training or environmental changes through a single faecal sample taken a day after the suspected stressor.
Read the full abstract on PubMed
Practical Takeaways
- •Fecal cortisol testing offers a non-invasive alternative to blood sampling for measuring stress response in horses, avoiding sampling-induced cortisol elevation
- •The validated commercial ELISA kit provides a reliable, cost-effective option for practitioners to assess stress levels in horses undergoing transport or other stressful procedures
- •Allow 24 hours post-stressor for detectable changes in fecal cortisol metabolites when using this measurement approach for stress assessment
Key Findings
- •Plasma cortisol increased significantly post-transportation (254.5 nmol/L) compared to baseline (142.8 nmol/L)
- •Fecal cortisol metabolites (FCMs) increased 24 hours post-transportation (10.8 ng/g) versus pre-transportation (7.4 ng/g)
- •The Arbor Assays DetectX Cortisol ELISA kit demonstrated analytical validity for equine plasma and fecal samples
- •FCMs detected stress-induced cortisol changes without the confounding diurnal rhythm observed in blood sampling