Objective Assessment of Acute Pain in Foals Using a Facial Expression-Based Pain Scale.
Authors: van Loon Johannes, Verhaar Nicole, van den Berg Els, Ross Sarah, de Grauw Janny
Journal: Animals : an open access journal from MDPI
Summary
# Editorial Summary: Facial Expression-Based Pain Assessment in Foals Objective pain assessment remains challenging in foals, yet accurate identification of discomfort is essential for welfare monitoring and clinical decision-making; van Loon and colleagues adapted an existing facial expression pain scale from mature horses to develop EQUUS-FAP FOAL, a systematic tool for evaluating acute pain in younger animals using video-based observation. The researchers assessed 59 foals (20 with acute clinical conditions, 39 healthy controls) across three blinded observers using 30–60 second video recordings, demonstrating excellent inter- and intra-observer reliability with Cronbach's alpha coefficients of 0.95 and 0.98 respectively. Foals with acute health problems scored significantly higher on the pain scale than controls (p < 0.001), and importantly, pain scores decreased measurably following NSAID treatment with either meloxicam or flunixin meglumine (p < 0.05). For practitioners, this objective tool offers a standardised, non-invasive method to quantify pain in foals where traditional vital sign changes may be subtle or delayed, potentially improving treatment decisions and welfare outcomes—though further validation studies across broader populations and conditions are warranted before widespread clinical implementation.
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Practical Takeaways
- •A validated facial expression pain scale (EQUUS-FAP FOAL) is now available for objective pain assessment in foals, improving welfare monitoring and treatment efficacy decisions
- •Video recordings of foal facial expressions provide a quick, non-invasive, blinded assessment method that could be used in clinical practice to objectively track response to pain treatment
- •This tool enables better monitoring of foal welfare and quality of life during acute illness, supporting earlier intervention and treatment optimization
Key Findings
- •EQUUS-FAP FOAL demonstrated excellent inter-observer reliability (Cronbach's alpha = 0.95) and intra-observer reliability (Cronbach's alpha = 0.98)
- •Foals with acute health problems had significantly higher pain scores compared to healthy controls (p < 0.001)
- •Pain scores decreased significantly after NSAID treatment with meloxicam or flunixin meglumine IV (p < 0.05)
- •Facial expression-based assessment from 30-60 second video recordings can objectively distinguish painful from non-painful foals