Highly Pathogenic Avian Influenza in Livestock

Overview from USDA

Highly Pathogenic Avian Influenza A (HPAI) H5N1 virus is an emerging disease in cattle. Federal and State agencies are moving quickly to conduct additional testing for HPAI (H5N1) virus, including viral genome sequencing to provide a better understanding of the situation to characterize the HPAI (H5N1) virus strain or strains associated with these detections as well as other components of this disease event at the connection between animals, people, and the environment. The genetic and epidemiological data indicate spillover of the virus from wild birds to dairy cows and some instances of spread from dairy to dairy and from dairy premises to poultry premises. Based on this analysis, we have learned that the whole genome sequence for virus found in positive herds in 8 states and on two recent commercial poultry premises in two different states indicates it is the same strain affecting both dairy cattle and poultry. While it is still unclear exactly how virus is spreading, the virus is shed in milk at high concentrations; therefore, anything that comes in contact with unpasteurized raw milk, spilled milk, etc. may spread the virus including other animals, vehicles, and other objects or materials. Therefore, both dairy and poultry producers should redouble biosecurity efforts and be vigilant about monitoring for and controlling disease in their herds and flocks.

Additionally, in order to continue to monitor and understand the extent of this virus and reduce the risk of further spread of HPAI H5N1, resulting in greater threats to poultry and livestock, APHIS issued a Federal Order on April 24, 2024 that requires premovement testing for lactating dairy cattle moving interstate and reporting of positive test results from all laboratories and State Animal Health Officials (SAHO). This document outlines both the interstate movement requirements, as well as APHIS recommendations to limit the spread. Updated laboratory guidance, including details on required reporting, are located on the APHIS website.

Our goal is to safeguard the health of U.S. livestock and poultry, protect the industry, keep our food supply safe, and protect public health and human safety based on the most up-to-date information we have. We continue to work diligently to understand the risk factors associated with this virus, transmission routes, and pathogenicity in cattle. This continues to be a rapidly evolving situation. USDA and Federal and State partners will continue to share additional updates as soon as information becomes available.


The United States Department of Agriculture (USDA) offers the following resources.

Indiana Board of Animal Health (BOAH)

  • H5N1 Influenza In Cattle
  • Sample Collection for Interstate Premovement Testing of Lactating Dairy Cattle (link from BOAH coming soon).

 Sampling and Submission

This guidance may change, so please check frequently for the latest information. If you have not done so already, we highly recommend joining our mailing list.

PLEASE CHECK WITH THE STATE OF DESTINATION ANIMAL HEALTH OFFICIALS to ensure that any additional requirements issued by the state destination are being met.

Please utilize the submission form: HPAI LIVESTOCK SUBMISSION FORM when submitting samples for premovement testing or clinically affected cattle. The submission form has been formatted for our laboratory to upload the animal IDs and other information – please do not change the formatting. We ask that submitters print a copy of the completed submission form and include it with the sample submission. Additionally, we ask that you save the Excel file in this format: VetLastName.Producer.CollectionDate.xlsx and email it to ADDL@PURDUE.EDU with the estimated arrival date and delivery method for the samples.

 APHIS Requirements for Interstate Movement of Cattle (rev. 4/26/2024)

Copied from the April 26, 2024 document linked above.

Interstate movements of lactating dairy cattle must follow the Federal requirements outlined below. Additionally, state-specific guidance for moving cattle must be followed. Clinical lactating dairy cattle are ineligible for interstate movement or movement to slaughter.

Nonlactating dairy cattle – including heifers, dry cows, and bull calves – are not currently subject to testing for interstate movement due to their risk profile.

Prior to interstate movement, lactating dairy cattle are required to receive a negative test for Influenza A virus at an approved National Animal Health Laboratory Network (NAHLN) laboratory using an NAHLN approved assay. The Indiana Animal Disease Diagnostic Laboratory at Purdue University is a NAHLN approved laboratory.

Sample Collection and Testing for Interstate Premovement Testing of Lactating Dairy Cattle
  • Samples are to be collected by an accredited veterinarian, or a state licensed veterinarian, or a sample collector approved by the appropriate state animal health official. Designated individuals on production sites can be trained to collect milk samples and nasal swab samples for diagnostic testing.
  • Samples must be collected under the supervision of a licensed or accredited veterinarian or as determined by the respective State Animal Health Official.
  • Milk samples: Samples to be collected include milk/udder secretions from individual cows. Each quarter is sampled and combined into one sample for submission to the laboratory. Submissions must be between 3-10 ml of milk per animal.
    • Pooling of milk samples can be done only at the laboratory.
  • For groups/lots of 30 or fewer animals moving interstate, all animals being moved must be tested. If more than 30 animals are moving interstate, then only 30 animals total must be tested.
  • Sample collection and testing must take place no more than seven (7) days prior to interstate movement.
  • Samples for interstate premovement testing need to be submitted to an approved National Animal Health Laboratory Network (NAHLN) Laboratory for testing. NAHLN laboratories will conduct NAHLN-approved PCR testing: FluA matrix, H5 and optionally Please see HPAI Livestock Testing Recommendations for details.
  • APHIS will reimburse for all interstate premovement testing at NAHLN laboratories; therefore, this testing at NAHLN laboratories will be completed at no cost to the producer/submitter.
  • At this time, APHIS is not reimbursing for sample collection or shipping.
 For Cattle with Positive HPAI Test Results
  • Lactating dairy cattle from herds which have tested positive for Influenza A are not eligible for interstate movement for thirty (30) days from the most recent collection of any sample that tests positive from any individual animal in the herd. After the 30-day period, animals must be tested again for movement.
  • If there are specific circumstances for isolating test-positive cattle and moving to another premises across state lines, this would need to be discussed and agreed upon with the respective State Animal Health Officials and APHIS.
 Cattle Moved Directly to Slaughter
  • Nonclinical lactating dairy cattle moving interstate direct to slaughter are not required to have a premovement test but must move on a certificate of veterinary inspection or other documentation of movement approved by the sending and receiving state animal health officials and provided to the sending and receiving state animal health officials.
  • Clinical lactating dairy cattle are ineligible for interstate movement or movement to slaughter.
 Sick or Clinical Cow Testing (rev. 4/26/2024)
  • Please contact the Indiana Board of Animal Health for guidance related to testing cows that meet the case definition and are suspect of Highly Pathogenic H5N1 Avian Influenza.


Samples should be packaged and shipped as Biological Substance, Category B to the ADDL including double bagging the samples and including absorptive materials.



Please contact the ADDL with any questions: 765-494-7440 or ADDLHPAI@purdue.edu.

Purdue University College of Veterinary Medicine, 625 Harrison Street, West Lafayette, IN 47907, 765-494-7607

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