A new report from the Farm Journal Foundation highlights a sobering reality: livestock disease outbreaks are not just animal health events - they are national threats to economic stability and food security. The top five livestock diseases, if left unchecked, could cost U.S. agriculture over $300 billion annually, underlining the urgent need for prevention, early detection, and coordinated response systems.

Stephanie Mercier, senior policy adviser at the Foundation, emphasizes that "protecting farmers and ensuring food supply chain resilience must be top national priorities."

Here are the five diseases identified as most threatening:

Foot-and-Mouth Disease (FMD): The $200 Billion Risk

Although the U.S., Canada, and Mexico are currently FMD-free, this highly infectious virus affecting cattle, pigs, and sheep remains a top concern. Past outbreaks in the UK, Taiwan, and recently Germany and Hungary show how easily FMD can cross borders.

A 2015 Kansas State University study estimated that a single FMD outbreak in the U.S. - without a robust emergency vaccine program - could result in economic losses approaching $200 billion. High-density livestock regions and interstate movement would make containment extremely difficult.

While FMD vaccines exist, WOAH protocols discourage their use in disease-free countries due to trade restrictions. However, the U.S. has stockpiled FMD vaccines following a 2018 farm bill provision.

African Swine Fever (ASF): Global Spread, Domestic Danger

ASF continues to expand across Asia and Europe, and in 2018, it wiped out half of China's swine herd, costing the economy $111 billion. A U.S. outbreak could lead to $80 billion in damages, especially with reduced exports and decreased demand for feed crops.

The presence of a large feral hog population complicates the threat further. Although no global vaccine has been widely implemented yet, the WOAH adopted standards for ASF vaccines in 2025, paving the way for long-term control.

New World Screwworm (NWS): A Creeping Threat from the South

After decades of absence, New World screwworm outbreaks are inching closer to the U.S., with recent cases detected just 120 miles south of the U.S.-Mexico border. The pest's larvae consume animal flesh, often causing severe wounds and infections.

The USDA projects a potential $1.8 billion loss to Texas's cattle industry alone if NWS crosses into U.S. territory. In response, the USDA has launched a five-part plan, including the release of sterile male flies from production centers in Tampico and Edinburg, Texas, a method used in the pest's original U.S. eradication in 1966.

Cattle imports from Mexico have been suspended, and beef prices could hit $10 per pound by late 2026, according to industry forecasts.

Highly Pathogenic Avian Influenza (HPAI): A Multi-Species Crisis

Since 2022, HPAI has reached all 50 U.S. states, affecting over 169 million birds by April 2025. The zoonotic disease - now found in poultry, hogs, cats, dogs, and even dairy cattle - is spreading faster than ever.

The last major outbreak (2014-15) cost over $1 billion, not including ripple effects in animal feed and land values. In 2025, egg prices surged by 350%, and the USDA remains cautious about potential milk market disruptions.

Porcine Reproductive and Respiratory Syndrome (PRRS): The Endemic Drain

PRRS has plagued the U.S. pork sector since 1987 and continues to cost the industry an estimated $1.2 billion per year, according to Iowa State University. The disease reduces litter sizes and weakens overall pig performance.

While vaccination and management can reduce losses, a breakthrough came in April 2025, when the FDA approved a gene-edited, PRRS-resistant pig. Although promising, commercial adoption is still years away.

Policy Gaps and What's Needed

The Farm Journal Foundation report identifies several systemic vulnerabilities in the U.S. biosecurity landscape:

• Lack of centralized outbreak response coordination

• Limited vaccine stockpiling and regulatory speed

• Inadequate veterinary training and field detection capacity

• Underfunded R&D for genetic resistance and biocontrol tools

"Investing in agricultural resilience is a matter of national security," Mercier writes. "Waiting until an outbreak occurs is too late."

For ag producers, co-ops, and policymakers, the message is clear: biosecurity is not optional. The ability to detect, respond, and contain these five diseases could determine the future of U.S. livestock production - and the stability of the entire ag economy.