Validation of the Zürich composite measure pain scale (ZCMPS) for abdominal pain assessment in cows

To validate the Zürich Composite Measure Pain Scale (ZCMPS) for assessing postoperative pain in cattle undergoing abomasal displacement surgery.

Prospective, randomised, blinded study.

A total of 14 video recordings from 11 cows that underwent laparotomy for abomasal displacement were included.

A group of six veterinarians with different levels of experience independently assessed the 14 videos. Videos were recorded 2, 6, 12 or 24 hours after surgery. The study consisted of four phases: training and phases I, II and III. In phases I and II, observers scored pain using the ZCMPS. In phase III, they applied a visual analogue scale (VAS) and indicated whether rescue analgesia was required (no/yes) based on clinical judgement. Real-time scoring by two additional observers was used for comparison against video-based assessments. Statistical analyses included intraclass correlation coefficients (ICCs) for inter- and intra-observer reliability, Spearman correlation between ZCMPS and VAS, Mann-Whitney U tests for video versus real-time scoring and receiver operating characteristic curve analysis to evaluate the ability of the ZCMPS to identify cows requiring analgesia.

The ZCMPS demonstrated excellent inter- and intra-observer reliability (ICC > 0.9, p < 0.001). Significant correlation was found between ZCMPS and VAS scores (rho = 0.7, p < 0.001), supporting construct validity. Sensitivity and specificity of the ZCMPS were 70% and 77%, respectively, when applying a threshold of ≥ 4/15 for rescue analgesia. Video-based scoring was comparable with real-time assessments, indicating robustness of the scale when applied remotely.

The ZCMPS is a reliable and valid tool for assessing abdominal pain in cattle with abomasal displacement. It can be used by observers with varying experience levels.