The zoologist Jordi Casamitjana looks at the horrendous method of mass killing of animals called “Ventilation Shutdown”, commonly used in the United States.
I don’t like horror movies.
I either find them too parochial, or too violent. I get why some people like them, though. It’s the roller-coaster effect. The fact that you receive sensory information that you may be in great danger, combined with a sense of relief that you have survived after the danger passed, sets up a series of hormonal reactions aimed at learning from this important experience so you can avoid the danger in the future. However, when you start to repeat the experience your learning processes get confused, as you seem to survive all the time. You are a “lucky” person as far as your reptilian brain is concerned, so you are somehow emotionally “rewarded”. You like the feeling, and you want to feel it again.
But, for some reason, this does not seem to work for me. Once I survive any “thrilling” dramatic experience, I tend to never get close to it again — the film The Exorcist that I watched as a child from under my parents’ dinner table when they thought I was in bed put me off all the other horror films.
Some people, though, as so exposed to horror that they get completely desensitised. They don’t’ react to it anymore. They don’t feel anything. In my opinion, those who have reached this level of desensitisation may become sociopaths or psychopaths if they no longer have any biological mechanism that allows them to stop harming others through empathy. I honestly think that some animal farmers — and perhaps some top vets — may have reached this stage. Even though hurting and killing animals is part of their normal routine, if they reach the point of no longer caring about how to kill the animals, no matter how much they suffer in the process, I think they may have crossed a very dangerous line.
I know, this may sound a bit extreme, but when you will learn about the subject of this article, you may arrive at the same conclusions as I did. This article is about something terrible that is happening in the US right now and possibly in other countries. It is something horrible that happens on animal farms. Something even worse than the average suffering farm animals are forced to endure in factory farms where they can hardly move, and they are killed when they are still very young. But this is not the product of deranged psychopathic criminals who are breaking the minimum animal welfare laws that direct farmers on how they can treat their animals “humanely”. This is actually legal and endorsed by the authorities. This is something the American Veterinary Medical Association (AVMA) often authorizes, even if they claim that it should only happen in exceptional circumstances. This practice is called “ventilation shutdown”.
What is Ventilation Shutdown?

You probably have experienced something that may help you to understand this concept. You may have been in a crowded room that was so hot and humid, that you could not bear it anymore. You found it difficult to breathe, and you thought you were going to faint. You tried to leave, but the exit was beyond reach. Perhaps a fan or opening a window might have given you, literally, a breather. Then, another day, when you heard the news of a dog who died of heatstroke after being left alone inside a car on a hot day, you remembered that feeling, and you were horrified and outraged. You imagined the dog crying for help, and nobody coming. What a betrayal of trust, you thought.
Well, what happened to those poor dogs is what happens to many animals on farms, but this time is not an accident. Ventilation Shutdown is an official way of killing farm animals on farms before they are taken to slaughterhouses if for whatever reason the farmers cannot take them there. It consists in keeping the animals indoors, shutting the doors and windows, turning off the airflow in the room, and letting the heat rise until everyone inside dies in prolonged agony. It’s the outrageous agony of the dog left in the car but multiplying the victims by hundreds or thousands. And those farmers who kill them in this way may just be following the instructions of the vets who say this is acceptable. How can this be?
Representatives of the top American veterinarian associations say that this method should only be used in special circumstances, but they seem to have made a norm from such exceptions now. One such circumstance has been the COVID-19 pandemic. When slaughterhouses became hotspots of infections, many workers fell ill and the slaughterhouses had to operate with fewer people. As they could not kill the same number of animals, some “farmers” chose to kill them using this horrible method. And if it was not COVID, then the swine flu pandemic. And if not that, then the avian flu pandemic.
The entire animal agriculture industry is now so rotten, with so many diseases being created there and spread due to the cramped conditions the animals are kept, and with so many social issues concerning their workforce, that it seems it is now in a permanent state of “exception” where all those supposedly more “humane” methods to kill animals have essentially been thrown off the board.
During ventilation shutdown, by adding extra heat into the unventilated rooms in the form of steam, some of the animals may even be scalded to death. The temperatures may rise as high as 49 degrees C (120 F), essentially baking the animals alive. In the US, farmers and vets use the initials VSD+ meaning ventilation shutdown plus heat (or plus CO2), so they do not even hide this anymore.
According to the Washington Post, “The American Veterinarian Medical Association’s guidelines said the method should be used as a last resort after others are ruled out. That it should be done quickly enough to kill 95% of the animals within an hour. And that all must be eventually killed.”
This is how Eric Gingerich, a veterinarian who specialised in chickens, defined this practice in 2015 as a method to tackle epidemics in birds: “Ventilation Shutdown (VSD) is defined as the cessation of natural or mechanical ventilation of atmospheric air in a building where birds are housed, with or without action to increase the ambient temperature. Birds die of hyperthermia….VSD will only be used as a last resort if normally used methods would not meet timing criteria…It is agreed that ventilation shutdown is not the ideal method for mass depopulation as it results in longer periods of time for suffering compared to other methods. The decision to use ventilation shutdown is only to be made after all other more humane methods have been considered and it has been determined that the time taken for other methods will allow the amount of virus to become excessively high and results in undue spread of the disease.”
Sadly, these hellish unscrupulous mass killings with heat are not uncommon in the US anymore. In the EU and the UK, birds are culled with CO2 gas or nitrogen-infused foam. EU officials have said VSD should not be used in the European Union, but there have been reports of farmers in France being given emergency permission to use it. In the US, though, it has been recently used more than ever.
Exposing Ventilation Shutdown

How do we know about all this? Thanks to whistle-blowers and animal protection investigators. And some of them have been arrested and prosecuted for exposing this cruel activity. Iowa’s prosecutors charged Matt Johnson, a Direct Action Everywhere investigator, for secretly placing cameras in Select Farms, a pig farm in Iowa, and recording how hundreds of pigs were killed using VSD+ in 2021. He also rescued a pig called Gilly in the process, so he was charged with burglary,
Fortunately, the court case against him was eventually dropped. However, he was not happy about this as he wanted to be able to show all his footage in court where the media would likely be present. Dropping the case prevented this, and perhaps this is why prosecutors did it. According to the Guardian, “He had hoped to use the trial to try to convince a jury that he was right to expose Iowa Select’s atrocities, create a precedent for the right to rescue suffering animals, and challenge the constitutionality of the ag-gag law he was charged under.”
In an op-ed article, Johnson wrote: “The state of Iowa falsely accused me of “terrorism” for exposing animal abuse. They’re lying about the food system, too…With the charges dismissed, I will not get to make my case before a jury of my peers and ask the government and industry to answer the deep and troubling questions that the state would prefer not to be asked.”
Dr Crystal Heath is a shelter veterinarian from Berkeley, California, and founded Our Honor, an organization that seeks to support and amplify the compassionate voices of veterinarians and other animal professionals who want to speak up for all animals. She saw the footage Johnson took and said to UnchainedTV the following: “It was a horror. One of the biggest animal welfare crises of recent years. And it wasn’t just one farm that did this. This was a nationwide catastrophe. Killing up to 10 million pigs via this method. The animals suffered for a prolonged period of time before dying of heatstroke…You have pigs for the first part screaming as the temperature rises. I’ve listened to all. There are 27 hours of audio coverage of this too. You can hear the pigs entering the barn. And then they are little snippets of video that they were able to get. They weren’t able to get video of all 27 hours because that’s just impossible to do. And gradually you hear the pigs screaming more and more.”
Dr Heath gathered the signatures of 1,500 veterinarians asking the AVMA to reclassify this method of killing animals as a not recommended form of depopulation (the euphemism used to mean mass killing to reduce numbers). However, the veterinary body seems to be ignoring them. There is now an entire organisation of veterinarians called Veterinarians Against ventilation Shutdown (VAVS) determined to change this.
After watching the DxE video, Glenn Greenwald wrote an article in the website Intercept about ventilation shutdown, where he said, “The Intercept, as the result of an investigation by animal rights group Direct Action Everywhere, or DxE, has obtained video footage of the procedure and the resulting carnage that occurred at one of the company’s facilities in mid-May. Additionally, a whistleblower employed by Iowa Select has provided extensive details to The Intercept about the extraordinary methods now being employed to kill pigs — agonizingly and over the course of many hours — in increasingly large numbers.”
The Massacre of Birds

If COVID-19 was the main excuse for the killing of pigs with ventilation shutdown during 2020 and 2021, the recent outbreak of bird flu has been the excuse for killing chickens, turkeys and ducks this year. In April 2022 it was reported that the number of farm birds killed in the previous two months in the US climbed to more than 24 million, with outbreaks reported nearly daily. As the goal was to destroy the birds within 24 hours to limit the spread of the disease, these massacres are often rushed causing a great deal of suffering — and this means VSD+. In June, the Guardian stated that 38 million birds had already been killed.
The Animal Welfare Institute (AWI) analysed US Department of Agriculture (USDA) data and found that 73% of culls in the US in February and March 2022 involved the use of ventilation shutdown. They considered it the “most inhumane method available.” USDA records show that eight of the 12 largest culls that used VSD+ between February and March took more than 48 hours to complete — the two largest culls took 7 and 16 days!
The last bird flu outbreak in 2015 — by the way, they are all caused by the animal agriculture industry —also involved killing millions of birds in the US, but they were mostly killed by CO2 poisoning or smothered in a blanket of firefighting foam. Why have they now chosen a much worse method? They blame supply shortages of CO2 and unhelpful farm designs. Dena Jones, director of AWI’s farm animal program, said, “In the current outbreak, [VSD+] — once considered an option of last resort — has become the default.”
In the last few months, there have been many protests about the killing of birds by ventilation shutdown. Activists from DxE have been interrupting NBA basketball games where the Minnesota Timberwolves played in Minneapolis, Minnesota, because Glen Taylor, the majority owner of the Timberwolves, has an egg farm that kills chickens using ventilation shutdown. DxE released a video about a mass killing of chickens with this method at Rembrandt Enterprises, an Iowa egg farm owned by Taylor. The Iowa Department of Agriculture confirmed that 5.3 million birds were destroyed in Buena Vista County, Iowa, where Rembrandt Enterprises is located. DxE investigators went to Rembrandt in March 2022 to document the reality of the chickens being killed. And they found, like all their predecessors, hellish scenes that will stay in their memories for life.
How has all this been allowed to happen? Why, despite all the exposés and protests, is still happening?
It is easy to just blame the evils of animal agriculture, and their corruptive power over governments and officials — including top vets who work for the farmers, not the animals they breed and kill. It is easy to blame money, and how farmers and vets have become intoxicated with greed —they only see the green of dollars and no longer the blood of sentient beings. But I find it hard to believe. I feel that something is missing here.
Perhaps all these people in charge have already crossed the line I mentioned at the beginning of this article. Perhaps they have become so desensitised, that they are now dangerous to society. If they allow animals to suffer that much under their watch, and they have so much power that can bake millions of sentient beings alive with impunity, perhaps we need to keep an eye on them because who knows what they would be doing next.
If there was a vegan world that I could move to, I would move there right now.
I don’t like horror farms.