USDA APHIS issued a Federal Order with requirements on testing for interstate movement of dairy cattle and mandatory disease reporting. The Wyoming Livestock Board provided the following information and links.


Federal Order announced by USDA APHIS

Issued: Wednesday, April 24, 2024 ----- Effective: Monday, April 29, 2024

Mandatory Testing for Interstate Movement of Dairy Cattle

  • In addition to a certificate of veterinary inspection, dairy cattle are required to have a negative test for Influenza A virus at an approved National Animal Health Laboratory Network (NAHLN) laboratory prior to movement. 
    • APHIS will cover the cost of testing at NAHLN labs. 
  • Herd owners in which dairy cattle test positive for interstate movement are required to provide epidemiological information, including animal movement tracing.
  • Dairy cattle moving interstate must adhere to conditions specified by APHIS.
  • These steps are required immediately (April 29th) for lactating dairy cattle, while requirements for other classes of dairy cattle will be based on scientific factors concerning the virus and its evolving risk profile.

Mandatory Reporting: 

  • Laboratories and state veterinarians must report positive Influenza A nucleic acid detection diagnostic results (e.g. PCR or genetic sequencing) in livestock to USDA APHIS.
  • Laboratories and state veterinarians must report positive Influenza A serology diagnostic results in livestock to USDA APHIS.

See link below for the full Federal Order. 


Situation Update

  • While the following types of transmission are documented, the exact method of transmission is still under investigation: 
    • Cow to cow 
    • Cattle premise to cattle premise 
    • Cattle to poultry
  • Pasteurization of milk has proven to inactivate the virus. Inactive virus does not cause infection and pasteurized dairy products remain safe to consume. See link to FDA webpage below for additional information. 




Information from WLSB

  • WLSB added HPAI in cattle to the WLSB Reportable Disease List
  • Report cattle with clinical signs to your veterinarian, immediately. Clinical signs of HPAI in cattle include: 
    • Decreased milk production
    • Thicker, concentrated, colostrum-like milk
    • Decrease in feed consumption with a decrease in rumen motility
    • Abnormal tacky or loose feces
    • Lethargy
    • Dehydration
    • Fever
    • Older cows in mid-lactation may be more likely to show clinical signs 

If you have any additional questions or concerns please contact Dr. Hallie Hasel, State Veterinarian at (307) 840-1389 or