It's the third outbreak in the country in recent weeks and the second on a farm owned by the Virginia-based company.

The disease was found this week on a farm in western Romania, near the Hungarian border. The farm has 15,000 pigs.

A local animal health official says that approximately 18,000 pigs will be slaughtered in the village. An earlier outbreak at another Smithfield farm in the same region prompted the slaughter of 20,000 pigs.

Smithfield has 25 pig farms in western Romania. The company said earlier this month that it's taking steps to limit the effects of the disease and was co-operating with authorities in the slaughter.

Smithfield is the largest pork producer in western Romania, where it has invested over one billion dollars.