On March 29, 2024, the Michigan Department of Agriculture and Rural Development (MDARD) announced that highly pathogenic avian influenza (HPAI) has been detected in a dairy cattle herd in Montcalm County, MI. This news came on the heels of a U.S. Department of Agriculture (USDA) announcement that the virus had been found in cattle in Texas, Kansas and New Mexico. Farmers report that cattle recover from the virus in about 10 days.  

According to USDA and the Centers for Disease Control and Prevention (CDC) pasteurized milk and milk products remain safe for consumption.   

According to the American Veterinary Medical Association, this is the first time that cattle have tested positive for HPAI, and only the second time HPAI has been detected in ruminants—a single goat tested positive earlier this month. Wild migratory birds are believed to be source of infection in the southwest. The infected Michigan herd received healthy cattle from a Texas farm on March 7. A local veterinarian verified that none of the shipped cattle were showing symptoms at the time of transport.   

Affected dairies reported the following clinical signs:  

• Reduced feed intake, with a simultaneous decrease in rumen motility 
• Reduced milk production 
• Cows experience thicker, concentrated, colostrum-like milk that may be discolored (yellow to brown) 
• Abnormal, tacky or loose manure  
• Low grade fever 

Producers who notice these signs in their herd should contact their veterinarian who can provide treatment recommendations, determine if testing is needed, and coordinate sampling with Michigan State University Veterinary Diagnostic Lab (VDL), 

MSU Extension dairy experts say that dairy and beef producers should revisit their biosecurity plants and tighten practices to help decrease the risk of disease outbreaks and illness. This includes: 

• Reporting any illness or deaths to your herd veterinarian 
• Minimizing the interaction with wild birds by incorporating management practices for wildlife 
• Cleaning and disinfecting tools and equipment used on farm 
• Isolating and monitoring the health of any new cattle brought onto a farm before introducing them into a new herd 
• Restricting nose-to-nose contact between livestock from other farms 
• Implementing a line of separation by minimizing the entry of vehicles, contaminated equipment, people, wildlife and other domestic animals onto the farm 

Example biosecurity plans, practices and resources for cattle can be found by visiting the Secure Milk Supply or the Beef Quality Assurance websites.  

Questions about biosecurity can be directed to MSU Extension educators: Jerad Jaborek, Phil Durst and Cora Okkema. Media questions should be directed to Beth Stuever, MSU Extension director of public affairs.