Overview: The U.S. Department of Agriculture (USDA), Food and Drug Administration (FDA) and Centers for Disease Control and Prevention (CDC), as well as state veterinary and public health officials, are continuing to investigate an illness among dairy cows that is causing decreased lactation, low appetite, and other symptoms. To date no similar illness, nor H5N1 detections, have been reported in Canadian dairy cattle.
Over the past weeks, H5N1 has also been detected in the U.S. in one dairy worker on an affected farm, cats on affected farms, and goats in one farm in MN (without reported links to affected dairy herds). Our understanding of H5N1 in North American mammals continues to grow. LINK

12th July 2024. Influenza A detected in Oklahoma Dairy Cattle, with Oklahoma becoming the 13th U.S. state to report infected dairy herd.  LINK

9th July 2024. Influenza A detections in U.S. Dairy Cattle. 140 cases in 12 states. LINK

26th June 2024. Influenza A detections in U.S. dairy cattle. 129 cases in 12 states. LINK

13th June 2024. Influenza A detections in U.S. dairy cattle. 102 cases in 12 states. LINK

7th June 2024. Influenza A detection in Wyoming Dairy Herd. LINK

6th June, 2024. Influenza A detection in Minnesota Dairy Herd.  LINK

5th June, 2024. Influenza A detection in Iowa Dairy Herd. LINK

4 June 2024. Influenza A detections in U.S. Dairy Cattle. 80 cases in 9 states. LINK

24 May, 2024. Influenza A detections in U.S. Dairy Cattle. 63 cases in 9 states. LINK

26 April 2024. Most recent detection of 34th infected dairy herd, in Colorado, in addition to previously reported detections in Texas, Kansas, New Mexico, Idaho, Michigan, Ohio, North Carolina, and South Dakota. LINK

2 April, 2024 Influenza A detection in Idaho Dairy Cattle  LINK

1 April, 2024 Influenza A detection in New Mexico Dairy Cattle LINK

March 29, 2024 HPAI detection in Michigan dairy cattle LINK

                           HPAI detection in Idaho dairy cattle LINK 

March 25, 2024  HPAI detection in Texas and Kansas dairy cattle LINK

The clinical case presentation that has been reported is:

1. Sudden reduction in feed intake with decreased ruminations evident on physical exam and rumination monitors.

2. Sudden decrease in milk production on a herd level. Individual cows that are more severely affected have milk that is yellow and concentrated with the appearance of colostrum.

3. Variations in manure consistency with the most common finding being tacky to dry manure, although some cows appear to have diarrhea.

4. Secondary infections such as pneumonia and mastitis.

The affected cases appear to be in lactation 2 or greater animals that are more than 150 days in milk. Calves, heifers, and dry cows appear not to be affected. Morbidity is around 10% of the animals. Cases present over a 7-10 day time period and the first herds report a return to near normal production in 3 weeks.

These symptoms have been reported by the American Association of Bovine Practitioners and the USDA-APHIS.

1st May 2024: Update on FDA testing of U.S. retail milk: "The FDA is announcing an additional set of results from our national commercial milk sampling study underway in coordination with USDA. The study includes 297 total retail dairy samples. New preliminary results of egg inoculation tests on a second set of 201 quantitative polymerase chain reaction (qPCR)-positive retail dairy samples, including cottage cheese and sour cream, in addition to fluid milk, show that pasteurization is effective in inactivating HPAI. This additional preliminary testing did not detect any live, infectious virus." LINK

April 26 2024 Preliminary culture results from retail milk samples testing qPCR positive for Avian influenza H5N1. 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.    LINK

April 25 2024. Initial results from FDA's nationally representative commercial milk sampling study. The agency continues to analyze this information; however, the initial results show about 1 in 5 of the retail samples tested are quantitative polymerase chain reaction (qPCR)-positive for HPAI viral fragments, with a greater proportion of positive results coming from milk in areas with infected herds. As previously noted and outlined in our summary below, qPCR-positive results do not necessarily represent actual virus that may be a risk to consumers. Additional testing is required to determine whether intact pathogen is still present and if it remains infectious, which would help inform a determination of whether there is any risk of illness associated with consuming the product. The FDA is further assessing any positive findings through egg inoculation tests, a gold-standard for determining if infectious virus is present. Early work by NIH-funded investigators indicates an absence of infectious virus in their studies of retail milk. To date, the retail milk studies have shown no results that would change our assessment that the commercial milk supply is safe. Epidemiological signals from our CDC partners continue to show no uptick of human cases of flu and no cases of H5N1, specifically, beyond the one known case related to direct contact with infected cattle. LINK

HPAI in cattle: Guidance updates for private veterinarians. Updates include:  
Until further notice, CFIA will cover the fees for laboratory testing at any CAHSN laboratory that is approved to test samples in domestic animals. CFIA does not pay for associated veterinary fees for sample collection or shipment to the lab. 
All non-clinical dairy cattle will now be eligible for testing. A milk sample is required for lactating dairy cattle and a nasal swab is required for non-lactating dairy cattle. 
For suspect case submissions, the private veterinarian is required to report negative test results back to the district office upon receipt.

LINK

CFIA Highly pathogenic avian influenza (HPAI) in cattle: Guidance for private veterinarians. This document serves as a reference for private veterinarians to collect and submit samples for highly pathogenic avian influenza (HPAI) in dairy cattle, both for suspect and non-clinical animals. It also includes information on reporting requirements for suspect cases of HPAI in cattle.  LINK

HPAI Update from the Government of Canada: In addition to the robust protective measures that already exist, the Government of Canada, in collaboration with stakeholders, is expanding its surveillance to manage the possible emergence of HPAI in Canada by:
requiring negative HPAI test results for lactating dairy cattle being imported from the United States to Canada.
conducting enhanced testing of milk at the retail level to look for viral fragments of HPAI.
facilitating the voluntary testing of cows that are not presenting with clinical signs of HPAI to facilitate enhanced industry biosecurity efforts. LINK

Highly Pathogenic Avian Influenza (HPAI) in Livestock: LINK

29 May 2024. Highly Pathogenic Avian Influenza (HPAI) H5N1Personal Protective Equipment Recommendations.   LINK

24 May 2024. USDA Expands Support for Producers to Stop the Spread of H5N1 in Dairy Cattle. LINK

10 May 2024 USDA HHS Announce New Actions to Reduce Impact and Spread of H5N1    LINK  

27 April 2024 Clarification Regarding Movement of Cattle Through Markets or Auctions to Slaughter, Under the April 24 Federal Order LINK

26 April 2024  

APHIS Requirements and Recommendations for Highly Pathogenic Avian Influenza (HPAI) H5N1 Virus in Livestock For State Animal Health Officials, Accredited Veterinarians and Producers LINK     

Testing Guidance for Labs for Influenza A in Livestock LINK tps://www.aphis.usda.gov/sites/default/files/hpai-livestock-testing-recommendations.pdf   

Federal Order on Interstate Movement FAQs  LINK    

25 April 2024. Federal Order on Interstate Movement in U.S. Dairy Cattle LINK 

Canada

Dairy Farmers of Canada and Animal Health Canada: HPAI: Biosecurity Recommendations for Dairy Farmers LINK

Update on Guidance on biosecurity measures for farm visits (2nd note)

proAction: Canadian Dairy Quality Assurance Program Biosecurity Module LINK

Canadian Food Inspection Agency Biosecurity for Canadian Dairy Farms: National Standard LINK

U.S.

Dairy Biosecurity Recommendations – HPAI and More_AABP LINK  

USDA-APHIS Secure Milk Supply (SMS) Dairy Biosecurity Resources LINK

Canadian Food Inspection Agency: Highly pathogenic avian influenza (HPAI) in livestock LINK

USDA-APHIS: Detection of Highly Pathogenic Avian Influenza in Dairy Herds: Frequently Asked Questions LINK

USDA-APHIS: Questions and Answers Regarding Milk Safety During Highly Pathogenic Avian Influenza (HPAI) Outbreaks   LINK