Quantitative assessment of increased sensitivity of chronic laminitic horses to hoof tester evoked pain.

The article discusses a study where researchers quantitatively assessed the increased sensitivity to pain of horses with chronic laminitis using a power-assisted hoof tester. The study found that it was possible to measure Hoof Compression Thresholds (HCTs) effectively and these measurements indicated that horses with chronic laminitis had consistently lower HCTs than normal horses.

Objective and Methodology

• The main objective of the study was to evaluate the use of a power-assisted hoof tester for quantitative sensory testing (QST) of horses’ feet affected by chronic laminitis.
• Hoof Compression Thresholds, or HCTs, were measured repeatedly on both chronic laminitic horses (seven in total) and normal horses (also seven) using a hydraulically powered and controlled hoof tester.
• Data were collected from two tests at three different sites in both forefeet over the course of three sessions.
• The collected data was then statistically analyzed using linear mixed models.

Results

• The mean HCT was found to be considerably lower for horses with laminitis compared to those without the condition. The variance was greater for the normal horses compared to the laminitic ones.
• The authors propose that averaging HCTs from each foot could produce a test with high reliability (as indicated by high intraclass correlation coefficients), excellent sensitivity and specificity.
• The authors also suggested that if the test detected a reduction of over 40% in the HCTs difference between laminitic and normal horses following effective treatment, these results would be statistically significant provided the experimental groups had nine or more horses.

Conclusions

• The authors concluded the HCTs can be safely and reliably measured using their hoof tester.
• They noted that the method could be potentially used clinically to identify changes in the HCTs of individual laminitic horses after further improvements, including simplification of the hoof tester and training of the horse.
• The authors also concluded that measuring HCTs could provide an additional method for assessing the effectiveness of treatments designed to alleviate chronic equine laminitis.