Vets and animal advocates in the US are calling for restrictions on “cruel” methods of culling birds, as farmers face killing millions of poultry due to a highly virulent avian flu tearing through the country.
In 2020, millions of farm animals were killed across the US after the Covid-19 pandemic shut down slaughterhouses and left animals stranded on farms. Now, bird flu, which has already led to the slaughter of millions of birds in Europe, is likely to result in another mass depopulation.
More than 50 million chickens and turkeys were killed after an aggressive bird flu outbreak in the US in 2015.
However, two commonly used methods to cull animals on-farm are attracting increasing backlash. The use of firefighting foam to suffocate animals and ventilation shutdown, in which animals are killed with extremely high heat and steam, are still permitted in the US, despite being effectively banned in the EU and labelled “inhumane”.
Poultry flocks sickened with avian flu are commonly killed with carbon dioxide poisoning or firefighting foam, where birds are smothered with a blanket of foam.
The European Food Safety Authority (EFSA) says the method involves “drowning in fluids or suffocation by occlusion of the airways” and is “not accepted as a humane method for killing animals”.
It is also not listed as a method of killing animals for disease control by the main animal health body, the World Organisation for Animal Health (OIE).
Ventilation shutdown, which has been described as “death by heatstroke”, was used to kill potentially millions of pigs during the Covid-19 pandemic. They were packed into sealed barns and killed with extremely high heat and steam.
The EFSA lists it among methods that “are likely to be highly painful” and “must never be used”.
In the EU, killing animals by suffocation or heat stress would be illegal, although it would be possible to obtain a derogation in an emergency when no suitable alternatives are available, said Peter Sandøe, a professor of bioethics at the University of Copenhagen.
In undercover recordings by the animal rights group Direct Action Everywhere (DxE) of ventilation shutdown taking place, pigs can be heard screaming as they are killed.
“I have treated animals with heatstroke and it’s horrible,” said Gwendolen Reyes-Illg, a veterinary adviser to the US-based Animal Welfare Institute. In cases of heatstroke, she explained, “chunks of mucosa and blood come pouring out of the rectum and vomiting of blood is common as well”.
Pork producers have maintained that ventilation shutdown was a last-ditch measure necessitated by the pandemic.
The American Veterinary Medical Association’s (AVMA) depopulation guidelines says the method should only be used if it can kill 95% or more of animals within an hour. However, Reyes-Illg said that in audio from the DxE investigation, sounds could be heard coming from the pigs after two-and-a-half hours.
News stories have described ventilation shutdown as “euthanasia”. But Reyes-lllg said: “It’s kind of Orwellian when you call cooking them alive euthanasia.”
Last year, a group of AVMA members submitted a resolution to classify ventilation shutdown as “not recommended”. A decision on the resolution has not been made, but animal welfare experts say it is time for US-wide rules to govern the treatment of farm animals before slaughter.
“That is the main difference when it comes to the EU, that we actually have common regulatory standards regarding the welfare of animals on farms, which are not found in the US at the federal level,” said Sandøe, who called the US’s use of ventilation shutdown “a big failure”.
Animals are killed on-farm for many reasons, not just disease control, for example due to illness or serious injury. More than 170 million chickens, pigs and cows die or are killed on-farm every year in the US, according to estimates from the National Agricultural Statistics Service.
Last month, DxE activists said they discovered a large number of piles of dead pigs discarded outside concentrated animal feeding operations (CAFOs) in central Iowa – potentially a result of the spread of an aggressive strain of porcine reproductive respiratory syndrome (PRRS), a deadly virus, in the midwest.
In one pile, activists said they found a three-week-old piglet still alive and rushed the animal to a vet, where it tested positive for PRRS. It also had a broken jaw and ribs.
It is impossible to know exactly what happened to the piglet, but activists say its injuries suggest it may have been “thumped,” a standard method used to cull sick or otherwise unwanted piglets by slamming them into the floor or ground or hitting them with a hard object such as a pipe.
The EFSA lists “disposal of pigs while still alive” as a risk associated with this and other cull methods if not carried out correctly. AVMA guidelines state that “failure to achieve 100% mortality in depopulation is unacceptable”, but reliable statistics on how many animals are thrown away while still alive are hard to come by.
Any new US-wide regulations around the killing of farm animals should protect workers too, say activists. According to one study, 10% of surveyed swine veterinarians involved in on-farm culling have thought about suicide and 23% reported needing mental health counselling.
In a 2020 video taken by DxE, in which activists spoke to farm workers the day after a ventilation shutdown, one worker simply said: “It’s terrible for everybody.”
