How does rat euthanasia occur? - briefly
Euthanasia in laboratory rats is usually achieved by delivering an overdose of a barbiturate anesthetic, such as sodium pentobarbital, via intraperitoneal injection, which induces rapid unconsciousness followed by cardiac arrest. This procedure follows AVMA guidelines to ensure a humane and painless death.
How does rat euthanasia occur? - in detail
The procedure for terminating laboratory rats follows established humane guidelines. Primary methods include inhalation of carbon dioxide, administration of an injectable barbiturate, and physical techniques such as cervical dislocation or decapitation. Each approach requires specific steps to ensure rapid loss of consciousness and confirmation of death.
Carbon dioxide inhalation is performed in a sealed chamber. The gas flow is calibrated to reach a concentration of 70 %‑80 % within a few minutes, causing loss of consciousness without distress. Continuous monitoring of respiratory rate and reflexes determines the point at which the animal becomes unresponsive. After the exposure period, the chamber is vented, and the animal is examined for the absence of heartbeat and corneal reflex.
Injectable barbiturate euthanasia involves a single intraperitoneal or intravenous dose of a high‑potency agent such as sodium pentobarbital. The recommended dosage exceeds 100 mg kg⁻¹, guaranteeing swift cerebral depression. Following injection, the rat is placed on a padded surface; loss of righting reflex and absence of breathing indicate the endpoint. Verification includes auscultation of the thorax and checking for lack of pupillary response.
Physical methods are reserved for situations where chemical agents are unavailable or unsuitable. Cervical dislocation requires precise placement of the thumb and forefinger at the atlanto‑occipital joint, followed by a swift, controlled separation of the head from the spine. Decapitation is executed with a sharp guillotine or scissors, delivering immediate severance of the spinal cord. Both techniques demand that the operator be trained and that the animal’s death be confirmed by the cessation of cardiac activity and reflex testing.
Post‑procedure handling includes placement of carcasses in biohazard containers, followed by incineration or approved disposal according to institutional biosafety protocols. Documentation of the method, dose, and verification results is mandatory for regulatory compliance and ethical oversight.