Anesthesia and analgesia protocols for zebrafish are critical welfare components of research using this species, with best practice rapidly evolving as understanding of fish pain sensitivity increases.
Zebrafish anesthesia welfare has advanced significantly as the species has moved from a perceived non-sentient research tool to a recognized welfare subject. The practical challenge is that anesthesia protocols developed primarily for efficacy and safety (avoiding overdose mortality) have not always incorporated analgesic elements for painful procedures. The emerging welfare standard requires that zebrafish research protocols include both appropriate anesthesia for insensibility during procedures and consideration of post-procedure analgesia for interventions expected to cause ongoing pain. Ethics committees reviewing zebrafish research protocols are increasingly requiring welfare justification comparable to that expected for mammalian research.