Requires specialized equipment (pressure-reducing regulator, CO₂cylinder or tank) and a closed chamber to contain gas.

May cause brief periods of distress before birds become insensible.

Birds should be placed in the chamber in a single layer. (MAC Cart)

Use in a well-ventilated area for operator safety.

Correct placement of the device on the head is critical.

Crushing of the neck bones is unacceptable prior to loss of sensibility.

This method is restricted to smaller birds
(e.g. ≤ 3 kg), although this may vary depending on operator ability.

Performed correctly (training and technique to be validated by a veterinarian), cervical dislocation results in the luxation (dislocation) – never crushing – of the cervical vertebrae.
Alternative methods should be considered (e.g. non-penetrating captive bolt) as in some classes of poultry there is evidence that cervical dislocation may not cause rapid loss of sensibility.
The site of the dislocation should be as close to the head as possible.
Cervical dislocation is difficult to perform correctly in large birds, and therefore may not result in immediate loss of sensibility. It is recommended that larger birds be rendered insensible prior to applying cervical dislocation.

Humane restraint methods (e.g. two people, appropriate restraint device) are necessary.

The impact must be of sufficient force and accurately placed in order to result in immediate insensibility and death in a single blow.

Due to the impact on operators and observers, other methods should be considered, especially when large numbers are to be euthanized.