Animal Welfare Science

Pain Assessment in Animals: Tools and Progress

The ability to accurately assess pain in non-verbal animals has improved dramatically with validated grimace scales and behavioral indicators now available for many species.

Key Facts

Grimace scales have been validated for mice, rats, rabbits, horses, sheep, cats, and pigs
The Mouse Grimace Scale uses facial action units similar to human pain expression
Pain assessment in fish is more challenging but behavioral indicators are being developed
Acute pain is easier to recognize than chronic pain in most species
Many animals receive inadequate post-operative pain relief due to poor assessment

Welfare Considerations

The development of species-specific pain assessment tools represents a major advance in animal welfare. These tools enable veterinarians and researchers to make evidence-based decisions about analgesia rather than relying on intuition or species-based assumptions. The challenge is translating validated research tools into routine clinical and farm practice where time pressure is significant.

What You Can Do

Support research into pain assessment tool development and validation
Advocate for pain assessment to be routinely used in veterinary and farm contexts
Ask veterinarians about pain scoring at any procedure your animals undergo
Donate to organizations developing pain assessment tools for under-served species