Veterinarians Are Saying Enough Is Enough as Avian Flu Exposes a Dark Side of Poultry Depopulation
As highly pathogenic avian influenza continues to sweep through poultry operations across the United States, veterinarians are finding themselves at the center of an uncomfortable conversation. The disease response playbook may be fast, but many in the profession argue it is far from humane. Under the USDA stamping out policy, poultry flocks presumed positive for avian influenza must be depopulated within 24 to 48 hours. In theory, this rapid response helps control viral spread. In practice, the methods used to carry it out have sparked growing outrage within the veterinary community.
One method in particular, Ventilation Shutdown Plus or VSD+, has become the focal point of concern. According to a 2022 paper, VSD+ quickly rose to become the most commonly used depopulation method in large commercial flocks. The process involves sealing poultry houses, turning off ventilation, adding heat, and leaving birds to die from heat stress over the course of several hours. USDA policy relies heavily on the American Veterinary Medical Association Guidelines for the Depopulation of Animals, last updated in 2019 with support from a USDA grant. Compliance with these guidelines is tied directly to indemnity payments, meaning producers are compensated only if they follow approved depopulation methods. Because VSD+ remains permissible under certain conditions, it continues to be widely used.
Dr. Crystal Heath, executive director of the veterinary advocacy nonprofit Our Honor, argues that this permissibility is the core problem. She has stated that while the guidelines say VSD+ should be limited to constrained circumstances, they fail to clearly define what those circumstances actually are. As a result, producers have little incentive to invest in alternatives that prioritize animal welfare. Heath also emphasizes a distinction that resonates deeply with many veterinarians. Depopulation is not euthanasia. Euthanasia is intended to relieve suffering, typically in animals that are already ill or compromised. In many avian influenza responses, birds are not clinically sick at the time they are killed, and the methods used do not meet the standard most veterinarians associate with humane death.
This discomfort is not fringe. A Veterinary Information Network poll of more than 3,000 veterinarians found that only 1.1 percent believed VSD+ is an ethical and humane method of depopulation. For a profession built on animal welfare, that statistic lands hard. Financial incentives further complicate the picture. Our Honor has compiled data on USDA indemnity payments linked to avian influenza depopulation. Jennie-O Turkey Store reportedly received around $120 million after depopulating flocks, some using VSD+. Hickman’s Egg Ranch in Arizona is believed to have received over $100 million. Critics argue that these payouts function as bailouts for large corporations that have chosen not to invest in more humane infrastructure.
Dr. Erin Zamzow, a Washington-based veterinarian, has pointed out that alternatives already exist. Nitrogen gas and high-expansion nitrogen foam can render birds unconscious within minutes, followed by death shortly thereafter. Compared to hours of heat-induced distress, these methods align far more closely with veterinary expectations of humane practice. Documents obtained through a Freedom of Information Act request by Our Honor show that VSD+ continues to be used regularly, despite its designation as a method reserved for constrained circumstances. For many veterinarians, this feels like a loophole that has swallowed the rule.
The controversy has intensified as the AVMA prepares to release a new edition of the depopulation guidelines. A draft released last year replaced the familiar categories of preferred, constrained circumstances, and not recommended with a tiered system. Tier 1 methods are prioritized, tier 2 methods may be used when tier 1 is not feasible, and tier 3 methods have limited or conflicting evidence regarding animal welfare.
In the draft, VSD+ appears as a tier 2 method for poultry and a tier 3 method for pigs. Heath and other critics argue that the new structure risks downplaying the welfare implications of these techniques rather than addressing them head-on. Many are calling for VSD+ to be clearly listed as not recommended across all species. As the AVMA prepares to publish the updated guidelines this month, veterinarians are watching closely. For a profession increasingly shaped by transparency, ethics, and public trust, the outcome will signal whether animal welfare remains a core value or a negotiable one when speed and scale enter the equation.
