Mass euthanization is coordinated by a government agency. Lots of people will be involved.

Where mass euthanasia is required, the chosen euthanasia methods must consider the animal welfare implications while meeting biosecurity requirements and minimising the risk of disease transmission.

It requires someone trained to handle the materials and equipment. Another person to confirm each animal has been euthanized. That can be veterinarians, but it can also be slaughterhouse workers or others skilled in the trade.

During a mass outbreak there is often a labour shortage of skilled experts. Third party non-government experts may be called in.

Recommend methods for mass chicken euthanization is filling an entire shed with carbon dioxide gas, then any survivors are hit with a non-penetrative captive bolt gun.