Bird Flu Detected in Cows: Safety of Drinking Milk Questioned by Experts

A mysterious cow disease in the US, initially believed to be the cause of thick and discolored dairy milk, has now been confirmed to be a bird flu outbreak. Highly pathogenic avian influenza (HPAI) has been identified in cows at four dairy farms in Texas and Kansas, with additional cases also confirmed in New Mexico. The exact number of affected farms and cows has not been disclosed.

Traces of the influenza virus were found in cow milk before pasteurization, but authorities assure that abnormal milk would never make it to market. This outbreak comes more than 15 years after a lab experiment showed that cattle are susceptible to bird flu. Previous studies have also shown evidence of cows being infected with human strains of H1N1, which resulted in reduced milk production.

The recent contagion among dairy farms in the US is unique and is suspected to have come from migrating avians. However, the Texas Department of Agriculture has stated that there is no threat to public health as contaminated milk is dumped and pasteurization effectively kills the virus. Scientists are currently sequencing the virus genome to determine its origin and how it jumped to cows.

In addition to cows, goats in Minnesota have also tested positive for H5N1. However, mammals are considered dead-end hosts for the virus. More than 200 cases of HPAI in mammals, including cows and goats, have been recorded since 2022. Fortunately, cattle are expected to fully recover from the virus, and there is no need to depopulate dairy herds, as stated by the Texas Department of Agriculture.