How does rat euthanasia proceed? - briefly
Rat euthanasia is usually carried out by first exposing the animal to an inhalant anesthetic such as isoflurane to induce unconsciousness, then administering a rapid intravenous injection of a barbiturate solution (e.g., pentobarbital) to cause cardiac arrest. The procedure must adhere to institutional animal care protocols and be performed by trained personnel to ensure a humane outcome.
How does rat euthanasia proceed? - in detail
Euthanizing a rat requires a reproducible, humane protocol that minimizes distress and ensures rapid loss of consciousness followed by irreversible cessation of brain activity. The procedure begins with preparation: verify that the chosen method complies with institutional animal care guidelines, gather all necessary supplies, and calibrate equipment. Personnel should wear appropriate personal protective equipment and be trained in both the technique and post‑mortem handling.
Selection of method
- Inhalation of carbon dioxide (CO₂) at a displacement rate of 10–30 % of the chamber volume per minute, gradually increasing to 30 % to avoid sudden hypoxia.
- Intraperitoneal injection of a barbiturate (e.g., sodium pentobarbital) at a dose of 150 mg kg⁻¹, delivered with a sterile syringe and needle of appropriate gauge.
- Cervical dislocation performed by a trained individual using a rapid, firm motion to separate the vertebrae, reserved for situations where chemical agents are unavailable.
Execution
- Place the animal in a transparent chamber for CO₂ exposure; ensure the chamber is sealed and the gas flow meter reads the correct rate.
- For injection, restrain the rat gently, locate the lower right quadrant of the abdomen, insert the needle at a 30° angle, and deliver the full volume in a single, smooth motion.
- If using cervical dislocation, hold the rat by the tail and support the torso, then apply a swift, downward force to the neck vertebrae while maintaining a straight spinal column.
Monitoring
Observe loss of righting reflex, cessation of movement, and absence of respiratory effort. In CO₂ chambers, confirm that the animal becomes unresponsive within 2–3 minutes; for injectable agents, check for lack of corneal reflex and muscle tone after 5 minutes. Record the time interval from initiation to confirmed unconsciousness.
Verification of death
Apply a secondary check: gently pinch the hind paw or assess cardiac activity with a stethoscope. Absence of heartbeat and respiratory sounds confirms irreversible death. Document findings in the animal’s record.
Disposal
Place the deceased rat in a sealed biohazard bag, label with species and date, and transfer to the designated incineration or deep‑freezing unit according to waste‑management protocols.
Adhering strictly to these steps ensures that the process is consistent, ethically acceptable, and compliant with regulatory standards.