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behaviour
nutrition
riding science
2020
Cohort Study

Association Between Disease Severity, Heart Rate Variability (HRV) and Serum Cortisol Concentrations in Horses with Acute Abdominal Pain.

Authors: Gehlen Heidrun, Faust Maria-Dorothee, Grzeskowiak Remigiusz M, Trachsel Dagmar S

Journal: Animals : an open access journal from MDPI

Summary

# Editorial Summary Researchers assessed heart rate variability (HRV) and serum cortisol as markers of autonomic nervous system activity in 43 horses presenting with acute colic, stratifying cases by treatment outcome: surgical intervention (n=18), conservative management (n=17), and euthanasia (n=8). Measurements were taken at admission, 24 hours post-admission, and at discharge, with HRV parameters and cortisol concentrations analysed using ANOVA with Bonferroni correction and Pearson correlations. Horses responding favourably to either surgical or conservative treatment demonstrated a progressive reduction in sympathetic tone over time, evidenced by decreasing heart rate and cortisol concentrations alongside increasing mean R-R intervals; conversely, horses requiring euthanasia showed significantly elevated heart rates and cortisol levels at admission and 24 hours, with no measurable improvement in these parameters. These findings suggest HRV analysis—a non-invasive technique requiring only standard electrocardiographic equipment—may help distinguish cases with poor prognosis from those likely to respond to intervention, potentially aiding clinical decision-making in acute colic scenarios; however, the authors acknowledge that further validation studies are needed before HRV can be confidently incorporated into routine colic assessment protocols.

Read the full abstract on PubMed

Practical Takeaways

  • HRV and cortisol measurements may help differentiate horses likely to respond to treatment from those with poor prognoses, potentially informing early treatment decisions
  • Monitoring changes in heart rate variability parameters over the first 24-48 hours could provide objective physiological markers of treatment response in colic cases
  • While HRV analysis shows potential clinical utility, practitioners should not rely on it as the sole diagnostic tool—further research is needed before implementing in routine colic assessment protocols

Key Findings

  • Heart rate variability parameters and cortisol concentrations showed decreased sympathetic stimulation over time in horses receiving surgical or conservative treatment, but not in euthanized horses
  • Mean NN interval and heart rate differed significantly between euthanized horses and treatment groups at admission and 24 hours post-admission
  • Treatment response (surgical or conservative) induced measurable changes in HRV and cortisol levels, whereas non-responsive horses showed no such adaptation
  • HRV analysis shows promise as a noninvasive marker of autonomous nervous system changes in equine colic, though further validation is needed

Conditions Studied

acute abdominal paincolic