Study sets tracheal pressure benchmarks in harness racehorses

Harness racehorses may soon have a more objective benchmark for upper-airway testing during exercise. In a prospective observational study published in Equine Veterinary Journal, researchers established reference values for inspiratory and expiratory tracheal pressures in 76 clinically normal harness racehorses during high-speed treadmill exercise. The team found that inspiratory pressures became significantly more negative as exercise progressed and were lower during poll flexion than during free head carriage, while expiratory pressures stayed relatively stable. The work was led by Hanna Vermedal and colleagues and focused on Standardbreds and Norwegian-Swedish coldblooded trotters, two breeds commonly used in harness racing. (pmc.ncbi.nlm.nih.gov)

Why it matters: For equine veterinarians, the study offers a practical reference set for interpreting tracheal pressure measurements during exercise testing, an area where comparison across cases has been limited by inconsistent baselines. That could help clinicians more objectively assess upper respiratory tract function, support diagnosis of dynamic obstruction, and track response to conservative or surgical intervention. The findings also reinforce prior work showing that poll flexion can increase upper-airway loading in harness racehorses, especially in breeds already recognized as vulnerable to dynamic laryngeal collapse. (pmc.ncbi.nlm.nih.gov)

What to watch: The next step will be whether these reference values are adopted in referral exercise-testing protocols and validated in horses with confirmed upper-airway disease. (pmc.ncbi.nlm.nih.gov)