Influenza A in Dairy Cattle

General Quarantine Order - Mandatory Milk Influenza A Testing
Mandatory Milk Influenza A Testing - Frequently Asked Questions

In response to reports of Influenza A virus affecting dairy cattle in multiple states (no PA herds have been affected at this time), PDA has developed a standardized response protocol for handling affected herds, including herds which may be located on a premises with poultry. Influenza A in cattle is classified as an “emerging” disease, and has recently been added to the Pennsylvania Dangerous Transmissible Disease list by temporary quarantine order.

Cattle or poultry suspects should be reported through the PDA emergency line, at 717-772-2852, option 1. The veterinarian on call will return your call ASAP.

Key points in the response protocol are below:

1. If clinical signs in the dairy herd meet the USDA case definition (see below), please contact your veterinarian, who should call the PDA emergency line immediately:
   • Sudden drop in feed intake in lactating dairy cows with concurrent decreased rumination and rumen motility.
   • Subsequent marked drop in herd level milk production. Cows may have thickened milk that appears colostrum-like or may produce very little or no milk.
   • Abnormal manure ranging from dry/tacky to diarrhea.
   • Cattle may also show respiratory signs, including a clear nasal discharge.
   • Cattle may also have a fever, and show signs of dehydration.
2. If sick or dead birds are present on the dairy premises:
   • If wild birds, contact the Pennsylvania Game Commission (1-833-PGC-WILD or 1-833-742-9453) or USDA Wildlife Services ( 717-236-9451) for assistance. These agencies may also be able to assist you with wild bird mitigation.
   • If domestic poultry, report to PDA using the emergency line at 717-772-2852, option 1.
3. If the dairy case definition is met, PDA will advise the herd veterinarian to collect samples for testing. In some cases the producer may collect samples under the supervision of the herd veterinarian if the proper sampling supplies are available. If the case definition is not met, the PDA on-call veterinarian will work with the herd veterinarian to investigate any other regulatory disease as appropriate.
4. Appropriate sampling for Influenza A testing in dairy cattle includes:
   • Collect samples from up to 10 affected animals and 10 unaffected cattle that are in milk. Unaffected cattle samples should be matched with parity and stage of lactation. Collect 3-10 ml individual milk samples in sterile tubes (preferred sample). Collect samples from all four quarters into one tube.
   • If milk cannot be collected from enough animals, collect one nasal swab per animal (for non-lactating animals) and place it in a suitable viral transport medium, including 3-5 ml PBS (phosphate-buffered saline), normal saline or BHI broth to test 20 animals total. Do not pool samples-use one swab from one animal per tube.
   • Have your herd veterinarian coordinate with PDA regarding testing at PADLS labs.
   • Samples which are collected by the producer must be submitted to PADLS with the veterinarian’s name included on the general submission form.
   • Producer should consult with their herd veterinarian to obtain the appropriate sample collection supplies.
5. For interstate movements, to meet the federal or state-specific requirements, testing can be requested from any of the PADLS labs by filling out the General form at Cattle Submission HPAI Form. Prem ID, individual animal IDs must be included. For milk collection, collect 3-10 ml milk from each quarter into a single sterile tube. Do not use tubes containing a preservative and be sure to avoid contamination of the sample. For non-lactating animals, use one swab per animal. After swabbing the nostrils, place the swab into a sterile tube containing 3-5 ml suitable viral transport medium (VTM). PBS (phosphate-buffered saline), BHI broth, or normal saline are acceptable. Ship the specimens on ice or drop off at the closest PADLS lab. Check with your herd/accredited veterinarian to obtain sample collection supplies and/or meeting other lab submission requirements.

PPE Letter by PDA and DOH
The PA Department of Agriculture and PA Department of Health have released recommendations for the use of PPE by dairy farm workers to limit exposure to the HPAI virus.
PPE Letter from PDA and DOH