Behaviour during transportation predicts stress response and lower airway contamination in horses.
Authors: Padalino Barbara, Raidal Sharanne L, Knight Peter, Celi Pietro, Jeffcott Leo, Muscatello Gary
Journal: PloS one
Summary
# Editorial Summary: Transport Behaviour as a Predictor of Stress and Respiratory Compromise An eight-hour journey induced measurable physiological stress in horses, manifesting as neutrophilia, elevated fibrinogen and globulin concentrations, and altered fluid-electrolyte balance; critically, behavioural observations during transport proved predictive of clinical outcomes. Twelve horses underwent pre- and post-transport assessment including clinical examination, arterial and venous blood sampling, and tracheal wash collection with both bacterial culture and microbiome analysis, whilst behaviour was continuously monitored before and throughout the journey. Horses displaying fewer head-lowering episodes and greater stress-related behaviours during transport exhibited significantly elevated serum cortisol and heart rate on arrival, increased tracheal mucus and inflammation, and higher bacterial concentrations in tracheal wash samples—indicating that behavioural passivity may signal maladaptation to transport stress. Additionally, six horses with abnormal lung auscultation post-transport had demonstrated elevated tracheal inflammation scores, higher overall bacterial concentration, and increased neutrophil percentage in tracheal secretions five days post-arrival, suggesting that pre-transport endoscopic findings may identify at-risk individuals. For practitioners, this research underscores the value of combining clinical assessment (pre- and post-transport auscultation and endoscopy) with vigilant behavioural observation during transit, as these markers together can identify horses at heightened risk of transport-associated respiratory disease and potentially warrant enhanced management or therapeutic interventions.
Read the full abstract on PubMed
Practical Takeaways
- •Monitor horse behaviour during transport — those showing reduced head-lowering and frequent stress behaviours are at higher risk of respiratory complications and should receive enhanced post-transport monitoring
- •Perform pre-transport respiratory endoscopy with tracheal wash on horses at risk; abnormal pre-existing tracheal inflammation and bacterial load are strong predictors of post-transport respiratory disease
- •Clinical auscultation and endoscopic examination before and after long journeys can identify horses developing transport-associated respiratory disease early, enabling timely intervention
Key Findings
- •Horses showing less head-lowering and more stress-related behaviours during transport had higher serum cortisol, heart rate on arrival, and tracheal bacterial concentration (P<0.05)
- •Eight-hour transportation caused significant acute phase response with neutrophilia, hyperfibrinogenaemia, and increased tracheal neutrophil proportion
- •Horses with abnormal lung auscultation post-journey had significantly higher pre-transport tracheal inflammation (P=0.017) and bacterial concentration (P=0.013)
- •Stress-related behaviours peaked in the first hour of journey while balance-related behaviours dominated the final hour