On Monday, the United States Department of Agriculture and the Centers for Disease Control and Prevention in conjunction with the Food and Drug Administration, announced an investigation into avian influenza showing up in the milk of dairy cows in multiple states.

The pathogen primarily causes illness in older cows and its symptoms include decreased lactation, low appetiteAvian and other symptoms.

Samples of milk from sick cattle at dairy farms in Kansas and Texas tested positive for bird flu, and a throat swab at another dairy in Texas tested positive for the highly contagious disease as well.

Additional testing began last week after farmers reported finding dead birds throughout their properties, according to the USDA.

The agency said federal and state agencies are working to sequence the virus genome to pinpoint the strain or strains of the virus.

"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 USDA said. "Dairies are required to send only milk from healthy animals into processing for human consumption; milk from impacted animals is being diverted or destroyed so that it does not enter the food supply."

A few weeks ago, health officials in Minnesota announced the discovered goats that had been on a farm with a bird flu outbreak had become infected with the virus. It is believed to be the first time bird flu was found in U.S. livestock.

Bird flu outbreaks in domestic poultry are normally remedied by killing the entire flock to eliminate the virus. However, livestock are able to recover on their own. Bird flu has been detected in various non-avian species and has infected humans on occasion.

Recently, the University of California-Davis and the National Institute of Agricultural Technology in Argentina reported that bird flu had adapted to spread to marine mammals after the deaths of elephant seals and seal lions in Argentina, Chile, and Peru.

According to the USDA, the commercial milk supply is safe and the risk of infection to people is very low.