Avian Flu Outbreak Illustrates How Factory Farming Threatens Animal Welfare and Public Health

Washington, DC—The deadliest avian influenza outbreak in seven years has already claimed the lives of an estimated 38 million domestic birds, mostly through “depopulations” at infected, crowded industrial poultry farms.

Faced with the surging H5N1 virus in February and March, producers overwhelmingly chose the most inhumane method available to kill their flocks—ventilation shutdown plus heat (VSD+)—according to an analysis by the Animal Welfare Institute (AWI) of USDA records obtained under the Freedom of Information Act.

Federal and state agricultural officials typically order the killing of birds exposed to bird flu. However, USDA policy requires that VSD+ only be used when other, more humane methods are not available. VSD+ involves turning off the airflow in a barn and ratcheting the heat above 104 degrees, leaving trapped birds to die from heat stress over several hours.

Although VSD+ likely causes extreme suffering and is opposed by 3,500 veterinary professionals, at least 73% of depopulations in February and March used this method to kill birds, according to AWI’s analysis of USDA data. The term “depopulation” is used to describe the rapid destruction of a population of animals in response to urgent circumstances, and is not to be confused with “euthanasia,” which literally means a “good death.”

“The killing of millions of sentient creatures by essentially baking them alive is a moral tragedy of immense proportions,” said Dena Jones, AWI’s farm animal program director. “This process can take hours and likely results in severe animal distress. Intentionally inflicting death in such a manner is unacceptable.”

Historically, the most common methods used to depopulate flocks were carbon dioxide gas (for killing caged egg-laying hens) and water-based foam (for cage-free chickens and turkeys).

In 2014-2015, avian flu was responsible for the worst animal disease outbreak in US history—resulting in the death of 50 million chickens and turkeys while costing taxpayers roughly $850 million and the US economy more than $3 billion. Following that outbreak, the USDA approved VSD+ in situations where no other method would accomplish flock depopulation within 48 hours.

“In the current outbreak, killing birds by inducing heatstroke—once considered an option of last resort—has become the default, because producers can’t destroy massive numbers of their animals fast enough to control the spread of disease,” said Jones.

During February and March, eight of the 12 depopulations involving more than 200,000 birds took longer than 48 hours, according to AWI’s analysis. The two largest depopulations of 2.8 million birds (in Wisconsin) and 5.3 million birds (in Iowa) took 16 and 7 days, respectively, to complete.

Since February, Iowa leads the nation in the number of birds killed by any depopulation method (nearly 13.4 million), followed by Nebraska (more than 4.8 million) and Pennsylvania (more than 4.2 million).

“Even mild strains of animal viruses can have a catastrophic impact, since they are able to mutate into variants capable of killing both animals and humans,” Jones said. “Factory farms are ideal incubators for disease—cramped, filthy warehouses for massive flocks or herds of animals bred to possess little genetic diversity. Yet producers remain unwilling to effectively plan for emergencies.”

“Clearly, the animal agriculture industry and the US government have learned little from previous outbreaks,” she added. “They continue to risk the welfare of animals and the health of the American public by allowing an unsafe, irresponsible production system to continue to operate with virtually no limits.”