More than 1,000 pigs have been seized from two farms in Chachoengsao's Muang district after testing positive for harmful agents administered to increase lean meat production, according to the Livestock Development Department.
More than 100 department officials were deployed to examine five pig farms and eight slaughterhouses in the district on Wednesday to determine whether they had fed the substances in question to their animals. The five farms are currently raising 7,659 pigs in total.
The deployment was ordered by department director-general Sorawit Thaneto, who instructed his deputy, Jeerasak Pipattanapongsophon, to lead the operation.
A total of 1,089 pigs raised in two of the farms returned positive results for the harmful agents through urine testing. The agents are known as beta-agonists and examples would include salbutamol and clenbuterol.
Officers said 160 pigs in the eight abattoirs tested negative.
Mr Sorawit said the operation zeroed in on areas where pig farming clusters as well as slaughterhouses and meat-selling facilities are concentrated. A similar operation had earlier been carried out in Nakhon Pathom, he said.
Futher examinations will be made in other provinces to ensure the public's safety, he said.
The use of such agents to feed livestock is punishable by up to three years in prison and/or a fine of up to 60,000 baht, as laid out in the Animal Feed Quality Control Act.
American pork has been banned in Thailand because of the use of ractopamine, an additive that also spurs growth of lean meat. The Thai government states there is not enough evidence proving the drug is safe for human consumption.
Thailand has long held a zero-tolerance policy on the use of beta-agonists, including ractopamine. The drug is also restricted or banned in 160 countries including some EU members, China and Russia.
The effects of ractopamine residue in humans is still unknown. But the drug has been linked to agitation, dyspnea (shortness of breath), cardiac issues, stress, disabilities and death in farm animals. It can pose a significant threat to consumers with a history of heart disease and high blood pressure.