200 dead cows were discovered in a field of Portage County, Wisconsin on Friday. The dead Cows were disposed using semi-trucks.

According to AP, officials said there is no threat posed to humans or other animals.

The owner of the dead cows has been working with a local veterinarian and thinks the animals died from the IBR/BVD virus. The virus can cause respiratory and reproductive problems.

More recent updates have suggested pneumonia as the reason of the cow's death, though such widespread cases of pneumonia are very rare. Tests are still underway to decide what is the real cause.