C9:ANALGESIA, ANAESTHESIA AND EUTHANASIA IN ZEBRAFISH – STEVEN VAN CRUCHTEN
LEARNING OUTCOMES
❖ You recall that there may be physiological and pharmacological interactions between analgesics and
anesthetics
❖ You recognize that in certain procedures or models, the administration of specific analgesics may be
incompatible with the scientific objectives
❖ You know that only a limited list of specified methods of humane killing of research animals is permitted by
legislation
❖ You recognize there are different methods for specific species and/or ages/weights and you can identify
appropriate methods for a given species and/or ages/weights
❖ You recognize that the method selected must be compatible with the scientific objectives
❖ You recognize that in addition to humane killing, confirmation of death is mandatory and you can identify at
least one appropriate method for confirming death in the relevant species and/or age/weight
DEFINITIONS
❖ Analgesia: “without” “pain”
o analgesics suppress the perception of pain BUT do not affect awareness, sensory perception etc.
o animals are still completely conscious and aware of what is happening with them and their
surroundings
❖ Sedation: “to sit”
o mild anesthesia for non-painful procedures such as handling, weighing, tagging, imaging…
o non-painful procedures = have a closer look at the fish, taking them out of the tank for
observation,…
❖ Anaesthesia: “without” “sensation”
o lack of awareness (general anesthesia) and sensation is blocked (including pain perception)
o the animal is not aware of its surroundings and does not feel any pain !!
❖ Euthanasia: “good” “death”
o humane killing
LEGAL CONTEXT
Directive 2010/63/EU
❖ Very general directives, they do not specifically tell you what to do → this is done to give the researchers
flexibility
❖ The methods should be done with the least amount of pain
o If you do painful procedures, you should always have general anesthesia !
❖ When should you use anesthesia? Take into account that you do not use any anesthetics that cause more
harm than good
❖ The knowledge on pain perception in fish is evolving → fish feel pain more than we thought at the
beginning, the procedures that involve pain perception are being reviewed and stricter rules are being made
to prevent the fish from hurting ! → animal welfare
1
LEARNING OUTCOMES
❖ You recall that there may be physiological and pharmacological interactions between analgesics and
anesthetics
❖ You recognize that in certain procedures or models, the administration of specific analgesics may be
incompatible with the scientific objectives
❖ You know that only a limited list of specified methods of humane killing of research animals is permitted by
legislation
❖ You recognize there are different methods for specific species and/or ages/weights and you can identify
appropriate methods for a given species and/or ages/weights
❖ You recognize that the method selected must be compatible with the scientific objectives
❖ You recognize that in addition to humane killing, confirmation of death is mandatory and you can identify at
least one appropriate method for confirming death in the relevant species and/or age/weight
DEFINITIONS
❖ Analgesia: “without” “pain”
o analgesics suppress the perception of pain BUT do not affect awareness, sensory perception etc.
o animals are still completely conscious and aware of what is happening with them and their
surroundings
❖ Sedation: “to sit”
o mild anesthesia for non-painful procedures such as handling, weighing, tagging, imaging…
o non-painful procedures = have a closer look at the fish, taking them out of the tank for
observation,…
❖ Anaesthesia: “without” “sensation”
o lack of awareness (general anesthesia) and sensation is blocked (including pain perception)
o the animal is not aware of its surroundings and does not feel any pain !!
❖ Euthanasia: “good” “death”
o humane killing
LEGAL CONTEXT
Directive 2010/63/EU
❖ Very general directives, they do not specifically tell you what to do → this is done to give the researchers
flexibility
❖ The methods should be done with the least amount of pain
o If you do painful procedures, you should always have general anesthesia !
❖ When should you use anesthesia? Take into account that you do not use any anesthetics that cause more
harm than good
❖ The knowledge on pain perception in fish is evolving → fish feel pain more than we thought at the
beginning, the procedures that involve pain perception are being reviewed and stricter rules are being made
to prevent the fish from hurting ! → animal welfare
1
