This virus is part of a type of Influenza A viruses that primarily affect birds. The highly pathogenic classification is based on the severity of the disease in poultry, but not in mammals such as pigs, cattle, or human. The current outbreak in domestic poultry, H5N1, has been occurring since 2022 and has been reported in 48 states, affecting over 82 million domestic birds; however, it’s not yet clear if the strain currently affecting dairy cows spread from the current outbreak in poultry. Rarely, the HPAI virus can spill over to mammals, including humans, with varying severity of clinical signs. At this point, there is nothing to suggest humans are at an increased risk from this particular strain. The risk remains very low for human illness. This is only the second time HPAI has been reported in ruminants. Since the disease impacts dairy cattle differently and less severely than poultry, the American Association of Bovine Practitioners (AABP) is recommending that we reference the disease in cattle as Bovine Influenza A Virus (BIAV).

Highly Pathogenic Avian Influenza (HPAI, or now called BIAV in cattle) is currently spreading to the bovine population, especially targeting mid-lactation cows. The source of this influenza has not yet been identified, but migrating waterfowl have been found to be reservoirs of the disease, and according to the USDA, are considered to be the disease source. Currently, there has been no single identified pathway, however, there are several probable transmission routes, such as: cows consuming contaminated feed or water. Water has a higher likelihood of transmission, due to the number of animals drinking from a communal water source.

Another less likely transmission pathway is via cows’ milk, whereby cow-to-cow transmission of diseased milk through operator or equipment contact could occur.

It’s all a matter of transmission. It is very likely that infected cattle frequently contaminate their water troughs with feces or saliva containing disease causing pathogens and that water troughs act as long-term reservoirs of the organism with a real potential for infection of cattle weeks or months later. Water troughs can be a communal reservoir of disease-causing pathogens, many times providing water to over 100 animals, where pathogens within the feed are located within close animal proximity.

The open water system is natural source, like drinking out of a pond or stream. A closed water system is like a well system, where the water has less availability to other animal access.

Water troughs should be cleaned often: The water quality in a water trough can be identified by the ORP value of the water. You should clean troughs minimally once a week by emptying all water from the tank. After emptying the tank, rinse the organic debris from the trough, followed by scrubbing it clean with hot water and with a chlorinated alkaline detergent. After scrubbing the trough, rinse out the trough and then follow with a chlorine dioxide-based product.

Suggested water trough cleaning directions:

1. 1. Empty trough of water and flush out organics.
   2. Prepare a bucket of hot water and / or a sprayer with cleaning solution (Chlor-A-Foam™). Solution should be warmer than 120˚ F (49˚ C), with a pH above 11.0.
   3. Spray foam or scrub cleaning solution on surface areas and let sit for 5 minutes. Scrub thoroughly.
   4. Rinse out trough of cleaning solution.
   5. If higher than a Score 2, spray trough with HabiStat™ (walls / base / water entry area) at 100 ppm concentration.
   6. Refill trough. Take ORP reading while refilling. ORP should be >600 mV

The solutions / processes are identified in the previous answer. Water treatment with an NSF certified product also provides a certified product identification and a method of testing the cleanliness and health of the water trough and water being consumed.

It’s not really algae growth, it is pathogen created biofilms that accumulate in a trough. The system can be cleaned, as outlined, and the water system can be treated with an NSF Certified product. Choosing a product certified by NSF lets you know the company complies with strict standards and procedures imposed by NSF. From extensive product testing and material analyses, every aspect of a product’s development is thoroughly evaluated before it can earn the NSF certification.

Most importantly, NSF certification is not a one-time event, but involves regular on-site inspections of manufacturing facilities and regular re-testing of products to ensure that they continue to meet the same high standards required to maintain certification over time. If for any reason a product fails to meet one or more certification criteria, NSF will take enforcement actions to protect the user, including product recall, public notification, or de-certification.

The cleaner the water trough, the less of the disinfecting solution that gets destroyed by the pathogen system. It is recommended that the water system be treated with an NSF Certified product to ensure that the water system / and the water consumed is free of disease-causing pathogens.

Water systems can be tested in several different ways. The most effective testing procedures are to measure the ORP (Oxidation Reduction Potential measured in millivolts (mV)) value of the water in a water trough, and if available, an ATP reading of a water trough. Both measurements can test the relative “health” of the water. The higher the ORP reading, the better the water value. The lower the ATP reading, the less pathogens that would be available.

Samples can be taken directly from the water source and / or the water trough for identification of pathogens present. The troughs can also be tested on the spot with ORP or ATP meters.

Depending on the lab, the water tests can show mineral presence in the water, and pathogen presence. In the cases of HPAI and BIAV, Veterinarian labs can show the pathogen levels of a solution.

You may notice a drop in feed intake, decreased milk production, or even changes in milk texture and color, characteristics similar to colostrum milk. Additionally, nasal secretions can be seen.

Work with your veterinarian to report cases of sick cattle to State Animal Health Official and their APHIS Veterinary Services Area Veterinarian in Charge. Veterinarians should submit samples to a national Animal Health Laboratory Network (NAHLN) laboratory for initial testing. Samples with non-negative test results are then submitted to the National Veterinary Service Laboratories (NVSL) in Ames, Iowa for confirmatory testing. USDA considers a positive test result from NVSL tests as confirmation, and NVSL carries out viral genome sequencing, as needed.¹

While you’ll likely see the greatest impact 3-7 days after an outbreak, feed intake is likely to come back after a few days. Somatic cell counts will likely return to pre-outbreak levels after 30-45 days.

The spread of the HPAI/BIAV within the Michigan herd indicated that bovine to bovine spread cannot be ruled out. As a result, dairy producers and veterinarians are encouraged to minimize dairy cattle movement. At this time, minimizing movement, upholding good biosecurity practices, and testing animals before necessary movements will limit disease spread to avoid the need for regulatory restrictions or quarantines. Unlike poultry flocks where HPAI is fatal, among dairies whose herds are exhibiting symptoms, the affected animals have recovered with little to no associated mortality reported.

Based on the information available at this point, we do not anticipate that this will impact the availability or the price of milk or other dairy products for consumers. Pasteurized milk is still safe to consume. Cows that show symptoms of avian influenza infection should have their milk dumped. No matter the concern, only milk from healthy cows is sent to processing for human consumption. Pasteurization kills the virus, making all pasteurized milk completely safe to drink.; unpasteurized, or raw milk can harbor dangerous microorganisms that can pose serious health threats to consumers.