Testing cattle for highly pathogenic avian influenza (HPAI)

Thursday, March 28, 2024

Modified April 23, 2024

On March 25, 2024, the USDA, FDA and CDC announced detection of highly pathogenic avian influenza (HPAI) H5N1 in dairy cattle in TX and KS. States with positive herds as of April 22, 2024, include TX, KS, ID, MI, NC, NM, SD and OH. Clinical signs have been limited to adult lactating cattle, with the primary sign being a pronounced drop in milk production, a decrease in appetite and rumination, mild respiratory signs, low grade fever, and thickened "colostrum-like" milk. Some cattle have dark tarry stools while others have diarrhea. Milk and nasal swabs from affected cattle have both tested positive for H5N1 clade 2.3.4.4b, the clade currently circulating in wild birds in the US since 2022. Some of the affected farms have also reported high numbers of dead wild birds. The Animal Health Diagnostic Center (AHDC), as a National Animal Health Laboratory Network (NAHLN) laboratory, tests avian and mammalian samples for HPAI by PCR, and forwards all non-negative samples to the National Veterinary Services Laboratories (NVSL) in Ames, Iowa, for confirmation. All confirmed positives are reported to the state veterinarian’s office of origin. In New York, positive results require quarantine of the affected premises. 

Veterinarians are encouraged to contact the AHDC Veterinary Support Services to discuss testing options with a diagnostic veterinarian. Fees for testing bovine specimens for HPAI by PCR are paid by the USDA. Please call 607-253-3900 or email vetsupport@cornell.edu for a consultation. When submitting samples, official premises ID must be included on the submission form. Contact the State Veterinarian's office to obtain a premises ID if the farm does not have one. 

How to submit for bovine HPAI testing:

  1. Call the Veterinary Support Services team at the Cornell AHDC, (607) 253-3900, to notify them that bovine HPAI samples will be submitted.
  2. Use a general submission form. Include the premises ID in the owner information box, all cattle IDs, and which specimens are being submitted from each animal. Under Cornell AHDC Acct. No. write: 544700. Write "Bovine HPAI" clearly in the test requested column.
  3. For all milk submissions, use vials with screw top lids (available through the AHDC supply center, 607-253-3935). Use an insulated shipping container. Ship overnight with cold packs. Place a copy of the submission form inside the box in a ziplock bag. 
  4. Write large "Fs" on all sides of the shipping box. 
  5. Email ahdcmammalfad@cornell.edu before 7am EST on the day the samples are due to arrive with the tracking number. Attach a copy of the completed submission form and a photo of the shipping label to the email. In the body of the email please write that you are sending samples for bovine HPAI testing.

Sample types from cattle (clinical suspects or screening):

  1. Milk - Individual cow: 5-10 ml per affected cow (do not pool from different cows)
  2. Nasal swab in plain red top tube with 0.5 ml saline, or viral transport media from affected cattle

Post-mortem sample types:

  1. Milk and mammary tissue
  2. Lymph nodes (supramammary and other)
  3. Lung
  4. Spleen
  5. Diaphragm
  6. Optional but ideal: full set of fresh and fixed tissues