By Melissa Cantor and Gino Lorenzoni
The highly pathogenic avian influenza (HPAI) virus affects several animal species, including migratory birds and domestic poultry. It has also been isolated from a variety of non-agricultural mammals, with the red fox, house mouse, and domestic cats being the most commonly affected species (USDA, 2025). In 2024, HPAI was first identified in dairy cattle, where it has continued to spread from farm to farm; at the time of this writing, 66 new cases have been confirmed within the past 30 days (USDA 2024). This new agricultural threat of HPAI has prompted producers to enhance their biosecurity and disinfection measures.
Below, we present information about HPAI and tips to safeguard your animals and business.
Virus Basics
- Animals infected with HPAI shed the virus in mucus, saliva, and manure. Infected dairy cattle shed high numbers of HPAI virus in raw milk.
- Pasteurization of milk inactivates the HPAI virus.
- The virus can be stable in organic matter such as manure.
- HPAI is susceptible to most disinfectants and detergents once the organic matter (manure) is removed.
- Cleaning boots and farm equipment to remove manure before disinfecting is essential!
- For dairy cattle, cases are documented in herds that regularly transport cattle between sites, and in herds that do not regularly transport cattle.
- HPAI may spread from farm to farm on people and their clothing, footwear, or vehicles.
- Fomites such as manured footwear and tires, as well as infected cattle can spread the disease.
- A few cases of HPAI have been documented in dairy and poultry farmers who were in extensive contact with sick animals and/or their secretions.
- The CDC is recommending that poultry and dairy farmers use protective eyewear, dedicated coveralls, and disposable gloves.