Assessment of acute and chronic pain in working horses and donkeys in Egypt and the influence of observer training.

Overview

• This study evaluated the effectiveness of training observers to assess acute and chronic pain in working horses and donkeys in Egypt using structured pain scoring systems.
• It also compared pain scores between working equids with or without pain and non-working equids to validate the pain assessment tools.

Introduction and Objective

• Working equids such as horses and donkeys often face welfare challenges, including pain from injuries or chronic conditions.
• Pain assessment is crucial for monitoring their welfare but requires reliable and objective methods.
• The study aimed to:
  • Assess the agreement in pain scores before and after observer training.
  • Evaluate whether pain scores differ between animals with acute pain, chronic pain, or no pain (fit-to-work) and compare these with non-working animals.

Methods

• The research was performed in two parts:
• Part 1 (Observer Training and Agreement):
  • Participants: 11 veterinarians and 9 veterinary technicians.
  • Procedure: Each observer scored pain in equids using a structured pain scale, both before and after receiving training on pain assessment.
  • Analysis: Agreement of each observer’s scores with established reference scores was measured using Intra Class Correlation (ICC), a statistic that reflects consistency and reliability.
• Part 2 (Pain Assessment in Equids):
  • Subjects:
    • 96 donkeys divided into fit-to-work (40), acute pain (21), and chronic pain (35) groups.
    • 104 horses divided into fit-to-work (42), acute pain (25), and chronic pain (37) groups.
  • Pain scores of these groups were compared to non-working equids to evaluate the scales’ ability to discriminate pain presence and severity.
  • Sensitivity and specificity were calculated to determine how well the pain scales detected animals truly experiencing pain versus those that were not.

Results

• Observer Agreement:
  • Technicians showed a significant improvement in agreement with reference scores after training:
    • Pre-training median ICC: 0.66 (range: 0.06 – 0.89).
    • Post-training median ICC: 0.89 (range: 0.44 – 0.93), statistically significant (P=0.024).
  • Veterinarians also improved, but the increase was not statistically significant:
    • Pre-training median ICC: 0.87 (range: 0.23 – 0.94).
    • Post-training median ICC: 0.92 (range: 0.48 – 0.93), P=0.096.
• Pain Scores in Equids:
  • Fit-to-work animals had similar chronic pain scores compared to non-working animals, indicating no apparent chronic pain symptoms.
  • Fit-to-work animals showed higher acute pain scores than non-working equids, suggesting low-level discomfort or normal pain responses associated with work.
  • Animals classified as having acute or chronic pain had significantly higher pain scores than fit-to-work animals (P<0.001), supporting the scales’ validity.
• Sensitivity and Specificity of Pain Scales:
  • Donkeys with acute pain: sensitivity 91%, specificity 73%.
  • Donkeys with chronic pain: sensitivity 83%, specificity 85%.
  • Horses with acute pain: sensitivity 92%, specificity 75%.
  • Horses with chronic pain: sensitivity 87%, specificity 81%.
  • These values indicate good performance of scales in correctly identifying animals with pain and in ruling out pain when it isn’t present.

Conclusions

• Training substantially improves the accuracy and consistency of veterinary technicians’ pain assessments in working equids.
• Structured pain scales effectively distinguish between animals with and without pain in populations of working horses and donkeys.
• These scales are useful tools for improving welfare monitoring of working equids in environments such as Egypt where these animals contribute significantly to livelihoods.
• Veterinarians show relatively high baseline agreement, but training can still improve reliability.

Implications

• The study supports the incorporation of observer training programs in clinical and field settings to enable better welfare assessments.
• Validated pain scoring systems help prioritize treatment and management of animals suffering from pain.
• Improved pain assessment can ultimately enhance the quality of life and productivity of working equids.