Skip to main content
  1. News Release

  2. Aug 15, 2022

Physicians Group Files U.S. Supreme Court Brief in Favor of California’s Proposition 12

Stressed farmed animals pose a significant public health risk, doctors say

WASHINGTON — The Physicians Committee for Responsible Medicine, a national public health nonprofit of more than 17,000 doctor members, filed an amicus brief with the U.S. Supreme Court on Monday, Aug. 15, in support of California’s Proposition 12, a law establishing confinement standards for pigs and other farmed animals.

In 2018, California residents overwhelmingly supported the initiative, which provides that a female pig must be permitted space to lie down, stand up, fully extend her limbs or turn around without touching the sides of the bars or another animal. 

The physicians’ brief argues that Proposition 12 advances a legitimate local health or safety interest and provides abundant evidence that the measure is in the best interest of public health.

“Prohibiting the intensive confinement of farmed animals reduces the risk of zoonotic diseases, those that spread from animals to people,” says Mark Kennedy, vice president of legal affairs for the Physicians Committee, who drafted the brief. “Tightly packed, unsanitary conditions cripple animals’ immune systems, increasing the risk that they will contract diseases, such as Salmonella, that can spread to humans.”

Examples of zoonotic epidemics caused by intensive production of farmed animals include the avian influenza virus H5N1 (“bird flu”), associated with intensive poultry farming, and the Nipah virus encephalitis outbreak originating from intensive pig farming. 

Routine use of antibiotics in farmed animals contributes to antibiotic resistance in humans. If Proposition 12 is upheld, fewer antibiotics will ultimately be used in pigs, and antibiotic resistance in humans may be mitigated. 

“This law promotes public safety; it protects the animals against contracting contagious and infectious diseases that threaten human health,” Kennedy explains. 

Despite the overwhelming support of California voters, the National Pork Producers Council and the American Farm Bureau Federation are challenging Proposition 12 in the U.S. Supreme Court, claiming it unconstitutionally regulates farmers in other states who ship meat to California.

The U.S. Circuit Court of Appeals for the Ninth Circuit rejected the national farming groups’ pleas to strike down Proposition 12 in 2021. The U.S. Supreme Court is set to hear oral arguments in the case on Oct. 11.

Media Contact

Kim Kilbride



Founded in 1985, the Physicians Committee for Responsible Medicine is a nonprofit organization that promotes preventive medicine, conducts clinical research, and encourages higher standards for ethics and effectiveness in education and research.

More on Environment