The Romanian authorities have ordered the slaughter of 20,000 pigs after an outbreak of swine fever at a farm in the west of the country.
The latest swine fever outbreak will not help Romanian meat exports
All farms in Timis county belonging to Smithfield Foods - one the largest US meat processors - will be inspected for signs of infection, officials say.
Road checks have been set up in the area to prevent the movement of meat.
Swine fever is a recurrent problem in Romania, which has been banned from exporting pork to other EU countries.
Timis official Ovidiu Draganescu said that all 25 farms belonging to Smithfield Foods will be tested for swine fever.
The virus has already been found in the Cenei farm, where the slaughter of pigs has already been ordered.
Swine fever is a highly infectious disease. Infected pigs must be slaughtered and the carcases buried or incinerated
Smithfield - which claims to be the biggest pork producer in the world - bought the Timis farms in 2004.
Animal health and food safety standards have been main concerns as Romania and Bulgaria joined the European Union on 1 January 2007.
The EU told both countries they would have to eradicate swine fever before they could sell pork in the rest of the EU without restrictions.