Preliminary evaluation of a behaviour-based system for assessment of post-operative pain in horses following arthroscopic surgery.

The research article focuses on developing an objective method to ascertain post-operative pain in horses that have undergone arthroscopic surgery. Utilizing behavioral analysis and physiological measures like heart and respiration rate, the study aims to identify signs of discomfort in the horses post-surgery.

Research Methodology

• The study was conducted on 12 adult horses divided into two groups: the first group underwent arthroscopic surgery, and the second group served as ‘pain-free’ controls.
• Horses in both groups were continuously filmed: 72 hours for the surgical group (including 24 hours pre-surgery and 48 hours post-recovery), and 24 hours for the control group.
• The researchers’ methods aimed to establish ‘activity budgets’ of the horses by evaluating their active behaviors and postures at set time points pre-surgery and post-recover for the surgical group, and at two time points for the control group.
• Heart rate and respiration rate of the horses were also recorded simultaneously to correlate physical reactions with behavior.
• Statistical analysis was used to investigate the alterations in behavior, heart rate and respiration rate within and between the two groups over time.

Research Findings

• The study found no significant difference in heart rate or respiration rate between the two groups at any time point.
• Alterations in behavior were observed in the surgical group due to effects of anesthesia and hunger from 0 to 6 hours post-recovery.
• All horses in the surgical group exhibited abnormal postures and locomotion in this period, whereas no such behavior was observed in the control group.
• Comparatively, horses in the control group spent more time eating and positioned towards the front of the stable, displaying less abnormal behavior.
• Observations also showed that post-recovery, the surgical group spent less time exploring, moving and in sternal recumbency.
• Within the surgical group, the researchers noted time-related behavioral changes such as increase in time spent with tensed lower lip, eating, and with head positioned above withers. However, no difference in repeated event behaviors was observed between the two groups.
• In the surgical group, the only olfactory behavior was seen to vary significantly with time.

Conclusions

• The study concluded that equine behavior showing signs of post-operative discomfort can be identified effectively through Direct Observation and Continuous Video Recording.
• Analyzing changes in the horses’ activity budgets was deduced to be a more sensitive method for identifying behavioral changes reflecting discomfort in horses, as compared to repeated observations of specific events and postures.