Changes in Heart Rate Variability with Induction of Gastric Ulcers in Adult Horses.
Authors: Louie Elizabeth Williams, Berryhill Emily H, Nieto Jorge, Wensley Fiona, Knych Heather, Finno Carrie J, Morgan Jessica M
Journal: Journal of equine veterinary science
Summary
# Editorial Summary Gastric ulceration represents a significant welfare challenge in athletic horses, yet our understanding of its systemic physiological effects remains limited. Williams and colleagues investigated whether experimentally induced gastric ulcers alter heart rate variability (HRV) as a marker of autonomic nervous system activity, enrolling eight horses in a randomised controlled design where half received omeprazole (2 mg/kg daily) and half received water over 28 days, with gastric ulcers deliberately induced through feed withholding on days 21–28. Ulcer severity increased substantially in untreated horses (P < 0.0001) but was significantly attenuated by omeprazole treatment (P = 0.0007), whilst treated horses demonstrated increased R-R intervals (P = 0.01) and critically, a reduced low frequency/high frequency ratio (P = 0.008)—indicating decreased sympathetic nervous system dominance through lower low-frequency fluctuations (P = 0.05). For practitioners, these findings suggest that gastric ulceration triggers measurable sympathetic activation, which omeprazole successfully counteracts; this has implications for understanding the physiological stress burden of ulcers and reinforces the importance of preventive treatment protocols in training programmes, though the small sample size (four horses per group) warrants confirmation in larger cohorts before drawing definitive clinical conclusions.
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Practical Takeaways
- •Horses receiving omeprazole during ulcer-inducing stress show measurable changes in heart rate variability that reflect reduced sympathetic nervous system activation, suggesting the drug mitigates stress responses associated with gastric ulcers
- •Heart rate variability assessment via electrocardiography could potentially serve as a non-invasive, field-applicable welfare monitoring tool for horses at risk of exercise-induced gastric ulceration
- •Athletic training protocols that include feed withholding appear to reliably induce gastric ulcers in horses; consider management strategies to prevent this common welfare concern in working equines
Key Findings
- •Gastric ulcer grade increased significantly with the induction protocol (P < 0.0001) and decreased with omeprazole treatment (P = 0.0007)
- •Omeprazole treatment increased R-R intervals (P = 0.01) and decreased the low frequency/high frequency ratio (P = 0.008) compared to water controls
- •Decreased low frequency fluctuations with omeprazole treatment (P = 0.05) suggest reduced sympathetic nervous system tone during ulcer induction
- •Heart rate variability analysis may be useful as a non-invasive indicator of gastric ulcer status and treatment response in horses