Their fate reads like a scene from a torture movie. A life of cruelty and confinement. A death that mirrors it: animals crowded into a sealed barn. The airflow is cut off. Then heat’s pumped in—and the temperature spikes above 104°F (40°C). They writhe and gasp, in pain and panic, trying to escape. They can’t.

This prolonged suffering is marketed as “ventilation shutdown plus” (VSD+). The “plus” of VSD+ indicates the addition of heat or carbon dioxide, as opposed to VSD, where the vents are sealed and the ventilation is simply switched off. Both are clinical terms that mask the brutality of the animal agriculture industry’s methods. (In a similar vein, the mass killings that happen through VSD+ are called “depopulations.”) ButVSD+is,putsimply,overheatinganimalsuntiltheyexperienceorganfailureanddie. The time to death varies in duration, but it can take hours.

Efforts to contain avian influenza (H5N1) have sparked these killings en masse. Why would the egg and meat industries put animals through this misery? Because it is convenient for them, and because they can. Since 2022, tens of millions of infected and uninfected birds across the US—including turkeys, caged egg-laying hens, and chickens raised for meat—have been killed this way.

In 2020, thousands of healthy pigs were killed using VSD+ (rather than being reared and slaughtered for meat). This was simply because the Covid-19 pandemic had upended supply chains, and it was suddenly more expensive to keep these animals alive than to kill them en masse.

Leaders at the American Veterinary Medical Association (AVMA) have endorsed this cruelty—even though VSD+ contradicts their oath to prevent animal suffering. By sending a strong message to the AVMA to remove its support for VSD+, we can help end one of the most egregious abuses of animals raised for food.