The Idaho State Department of Agriculture (ISDA) identified today highly pathogenic avian influenza (HPAI) in a Cassia County dairy cattle operation.

These are the first cases of HPAI in a livestock operation in Idaho. The affected facility recently imported cattle from another state that has identified cases of HPAI in cattle, which suggests the virus may be transmitted from cow-to-cow, in addition to previous reports indicating cattle were acquiring the virus from infected birds.

The primary concern with this diagnosis is on-farm production losses, as the disease has been associated with decreased milk production.



Symptoms of HPAI in cattle include:

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


At this stage, there is no concern about the safety of the commercial milk supply or that this circumstance poses a risk to consumer health. The pasteurization process of heating milk to a high temperature ensures milk and dairy products can be consumed safely.

The ISDA encourages all dairy producers to closely monitor their herd and contact their local veterinarian immediately if cattle appear to show symptoms. HPAI is a mandatory reportable disease, and any Idaho veterinarians who suspect cases of HPAI in livestock should immediately report it to ISDA at 208-332-8540 or complete the HPAI Livestock Screen at agri.idaho.gov/main/animals/hpai/.

It is recommended to enhance biosecurity measures across all livestock facilities in Idaho. Biosecurity practices can be found at agri.idaho.gov/main/animals/hpai/.

For decades, Idaho has worked diligently to implement industry-driven programs that mitigate the transmission of diseases that cause on-farm economic losses. ISDA’s response to the detection of HPAI in cattle aligns with standard ISDA animal disease detection procedure.

This is an evolving situation, and additional updates will be provided by ISDA as they become available.