HPAI testing to be required for lactating dairy cattle before transportation

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The US Department of Agriculture’s (USDA) Animal and Plant Health Inspection Service (APHIS) announced it will soon be requiring dairy cattle to be tested for highly pathogenic avian influenzas (HPAIs), more specifically avian influenza type A H5N1. As of April 29, 2024, laboratories and state veterinarians are required to report positive test results for Influenza A in livestock.¹

The test will initially apply to lactating dairy cattle depending on the evolving understanding of the disease and the risks associated with it. Recently,¹ the FDA confirmed the presence of HPAI virus remnants in milk that is commercially available coming from areas with a higher number of positive test results for infected herds.

“The FDA has received additional results from an initial limited set of geographically targeted samples as part of its national commercial milk sampling study underway in coordination with USDA. The FDA continues to analyze this information; however, preliminary results of egg inoculation tests on quantitative polymerase chain reaction (qPCR)-positive retail milk samples show that pasteurization is effective in inactivating HPAI. This additional testing did not detect any live, infectious virus. These results reaffirm our assessment that the commercial milk supply is safe,” the FDA disclosed in a public statement.²

At this time, researchers are continuing to try and get a better understanding of the transmission of the disease and its origins in cattle, cats, and other mammals through federal agencies and partners. On April 24, 2024, the USDA APHIS announced a federal order to prevent the spread of HPAI after 22 states implemented their restrictions on dairy cattle traveling from different states or premises when the virus is known to have infected dairy cattle.³ Now, dairy cattle that are lactating will be required to have a negative test result for influenza type A virus performed by an approved National Animal Health Laboratory Network (NAHLN) laboratory.

If a herd owner has a positive test, they will be required to provide epidemiological information, including animal movement tracing. The positive lactating cattle will also not be permitted for interstate movement for 30 days from the most recent sample collection that was the source of the positive test.¹ Once the 30 days is complete the cattle must be tested again if they still wish to be transported.

APHIS also disclosed it will reimburse for testing at NAHLN laboratories, including samples submitted for the following:¹

• Dairy cattle suspected of the disease because of clinical signs
• Premovement testing
• Samples from other animals on dairy farms that are associated with the current disease event
• Producers curious about the disease status of asymptomatic animals

Results from the testing should be returned within 1-3 days and any non-negative samples will undergo confirmation testing at the USDA’s National Veterinary Services Laboratories and should be returned within a day or 2.

References

1. USDA requires HPAI testing for lactating dairy cattle before movement, reporting for all livestock. News release. American Veterinary Medicial Association. April 26, 2024. Accessed April 29, 2024.
2. Updates on Highly Pathogenic Avian Influenza (HPAI). News release. US Food and Drug Administration. April 26, 2024. Accessed April 29, 2024. https://www.fda.gov/food/alerts-advisories-safety-information/updates-highly-pathogenic-avian-influenza-hpai
3. McCafferty C. Multiple states announce cattle import restrictions. April 10, 2024. Accessed April 29, 2024. https://www.dvm360.com/view/multiple-states-announce-cattle-import-restrictions