Anaesthesia and Pain Management in Laboratory Rodents

Refinements in anaesthesia and analgesia for laboratory rodents represent some of the most impactful welfare improvements available in biomedical research today.

Key Facts

Rats and mice constitute over 80 percent of all animals used in biomedical research globally
Inadequate analgesia post-surgery is a documented problem in many research institutions
Pain in rodents affects experimental results, compromising both welfare and scientific validity
Signs of pain in mice include a hunched posture, piloerection, and reduced activity
The Mouse Grimace Scale allows reliable non-invasive assessment of acute pain in mice
Modern anaesthetic protocols adapted from veterinary practice reduce recovery time and distress
Many institutions are moving toward multimodal analgesia combining opioids and NSAIDs

Welfare Considerations

Historically, pain management in laboratory rodents was underemphasized, partly because rodents hide signs of pain as a survival strategy and partly due to concerns that analgesics would interfere with experiments. Evidence now strongly indicates that unmanaged pain in rodents causes physiological and behavioral changes that actually compromise experimental reproducibility — making analgesia both a welfare and scientific imperative. Anaesthetic deaths, which are preventable with proper monitoring, represent an additional welfare and resource waste. The adoption of validated pain assessment tools like the Grimace Scale has transformed pain recognition and management in leading institutions.

What You Can Do

Support funding for development and validation of rodent pain assessment tools
Advocate for mandatory post-operative analgesia protocols in institutional guidelines
Choose cosmetic and personal care products not tested on animals
Support Three Rs centers that develop alternatives and refinements for rodent research
Advocate for requiring pain management training for all laboratory animal researchers