Highly Pathogenic Avian Influenza in Cattle

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For media inquiries, contact Sydney Kennedy by email at media@isda.idaho.gov or phone at 208-332-8507

Highly Pathogenic Avian Influenza Detected in Idaho Cattle

The Idaho State Department of Agriculture (ISDA), has identified highly pathogenic avian influenza (H5N1) in dairy cattle operations. The table below shows the counties with current quarantines in place.

Transmission of the virus is likely a multi-factor event including, but not limited to, direct contact (cow-to-cow), fomite related (boots, trucks, equipment, etc), ventilation/housing environment and possibly also continued exposure to infected wild birds. The primary concern with an HPAI diagnosis in dairy cattle is on-dairy production losses, as the disease has been associated with decreased milk production.

Symptoms of H5N1 in cattle include:

    • Drop in milk production
    • Loss of appetite
    • Changes in manure consistency
    • Thickened or colostrum-like milk
    • Low-grade fever

ISDA Response

One of ISDA’s primary goals is to support industry-driven programs that mitigate the transmission of diseases that cause on-farm economic losses. ISDA’s response to the detection of H5N1 in cattle aligns with standard animal disease detection procedure.

Lactating dairy cattle on affected facilities are quarantined when H5N1 is confirmed by official test results. Following quarantine, ISDA works with producers and their vets to develop a testing and surveillance strategy to monitor the herd and number of affected animals.

The infected cattle are being quarantined from the rest of the herd on the facilities. Pasteurized milk from affected cows does not present a human health concern, and the cows on the dairy will continue to produce milk and all animals will be cared for normally.

There are additional import requirements for lactating dairy cattle.

What Livestock Producers Can Do

    • Enhance biosecurity measures.
    • Closely monitor your herd for the following symptoms:
      • Fever
      • Lethargy
      • Loss of appetite
      • Constipation
      • Thickened or colostrum-like milk
      • Decreased milk production
    • Use discretion when purchasing new livestock and introducing new animals into your herd. New additions should be isolated from the existing herd for 3-4 weeks.

If your cattle appear to be infected

  1. Contact your local veterinarian immediately.
  2. After talking with your veterinarian, fill out the H5N1 Livestock Screen.
  3. Once the screen is submitted, an ISDA veterinarian will review the screen to determine if ISDA assistance is needed. Direct assistance from ISDA will be dependent on the severity and size of the herd as well as the availability of ISDA veterinarians.
Consumer Safety

The FDA and USDA continue to emphasize that the commercial milk supply is safe. The pasteurization process has been shown to destroy and inactivate the H5N1 virus. Additionally, milk from sick cows is being diverted and destroyed so that it cannot be used for human consumption. The federal-state milk safety system, and the Grade “A” Pasteurized Milk Ordinance, have proven effective for decades against a wide range of pathogens.

Based on the limited research and information available, we do not know at this time if H5N1 viruses can be transmitted through consumption of unpasteurized milk and products made from raw milk from infected cows. Before choosing to consume unpasteurized milk products, it is important to consult with your raw milk producer.  

Currently quarantined facilities in Idaho


# of Facilities

















Twin Falls


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