Solving a Cow Sickness Whodunit

Dr. Barb Petersen ('09) & Dr. Drew Magstadt ('11)

In February, dairy cattle in multiple Texas herds were suddenly producing less milk and the typically voracious eaters had seemingly lost their appetites. For weeks, Dr. Barb Petersen sought an answer before she messaged Dr. Drew Magstadt, clinical associate professor in Iowa State's Veterinary Diagnostic Laboratory. When the testing in Texas failed to find any clues, Magstadt and Petersen concluded that a likely cause was ill-made food. Then the cats on the dairy farms started dying from swollen brains, a potential result of influenza. When Magstadt tested milk samples Petersen sent him, it confirmed avian influenza as the cause of death. Further testing and retesting confirmed that the virus affecting the dairy herds is the type that has been driving poultry outbreaks. "There's plenty of times that we get called in to these types of situations, and sometimes we strike out," Magstadt said. "The times that we do find something, it's very rewarding."