The Washington PostDemocracy Dies in Darkness

Opinion Why are we accepting the mass slaughter of animals through heatstroke?

Chickens stand in their cages at a farm near Stuart, Iowa, in 2009. (Charlie Neibergall/AP)

Brian Collins is a faculty member at the Cornell University College of Veterinary Medicine and a veterinarian at Farm Sanctuary. Lauri Torgerson-White is an animal welfare scientist and research director at Farm Sanctuary.

As a result of the avian influenza outbreak this year, the Agriculture Department has ordered the killing of almost 38 million chickens, turkeys, ducks and geese to stop the spread of the virus. The agency claims this is an unfortunate necessity to protect uninfected birds living on U.S. farms. But how we carry out the task says a lot about who we are as a society.

Here’s the wrong way to do it: killing the birds en masse by subjecting them to heatstroke. Yet such inhumane treatment of animals is not only common, it is supported by the American Veterinary Medical Association (AVMA), the organization that recommends best practices for the industry.

The mass slaughter technique, euphemistically known in the industry as ventilation shutdown plus (VSD+), is brutal. It involves sealing up a barn full of birds, turning off the ventilation system and turning on the heat. As the temperature rises, the birds, who are already stuffed together at unnaturally high densities, begin to pant, flap their wings and jump around, as if trying to escape. They eventually fall to the ground, mercifully unconscious. Most chickens suffer for up to two hours before succumbing to heatstroke.

The AVMA is not a regulatory agency, but the industry uses its guidelines to justify the practice. Its guidelines classify methods for mass killing — or “depopulation,” as the organization terms it — into three categories: 1) preferred 2) permitted in constrained circumstances and 3) not recommended. Methods which are “permitted in constrained circumstances,” the organization states, should only be used “when the circumstances of the emergency are deemed to constrain the ability to reasonably implement a preferred method.” The constraints include, “but are not limited to, constraints on zoonotic disease response time, human safety, depopulation efficiency, deployable resources, equipment, animal access, disruption of infrastructure, and disease transmission risk.” The recommendation seems purposefully vague to allow the industry to utilize these methods anytime the preferred methods are not easily implementable — which, it turns out, is most of the time.

Death by mass heatstroke, the most common technique used during this year’s avian outbreak, is particularly unconscionable because of how long animals must suffer before dying. The method was used to kill pigs during the supply chain disruptions that occurred during covid-19 outbreaks at meatpacking facilities. A case study of almost 250,000 pigs published in the Journal of the American Veterinary Association found that the average time from the beginning of the process until the pigs were silent, and presumably dead, was approximately one hour. For some, the process took as long as 83 minutes. More than 700 pigs still requiring manual killing afterward. Undercover footageof the process at an Iowa hog farm shows the pigs squealing in distress with temperatures reaching 120 degrees Fahrenheit.

If that isn’t sufficiently outrageous, consider this: Taxpayer dollars are being used to carry out the practice. The Agriculture Department has devoted hundreds of millions of dollars to bird flu response activities, including these mass killings. While the agency has agreed that overcrowding animals can increase influenza transmission, they have failed to take meaningful action to prevent overcrowding.

Instead, the agency encourages farmers to “consider reducing the number of birds in poultry houses as part their best management practice.” Additionally, it has settled a lawsuit challenging its irresponsible bird flu response plan — brought by our organization, the Humane Society of the United States and Mercy For Animals — by agreeing to assess the environmental impacts of the plan and consider how killing and burying or burning millions of birds threatens wildlife, habitats, water and air quality and human health.

There are some Americans, unfortunately, who will find it hard to care about how animals sentenced to death are slaughtered. We implore them: Why should we accept such cruelty? Would they support the mass killing of cats and dogs in this torturous way? We doubt it. As such, the AVMA should denounce this practice and prioritize the well-being of animals.