South Korea has culled over 6 percent of poultry in the country to curb a bird flu outbreak that has hit farms and migratory birds nationwide, government officials said on Friday.

That brings the total number of farm birds slaughtered to 10.16 million, close to a record 10.2 million during an outbreak in 2008, according to data from the agriculture ministry.

No human infection has been reported, but a dog tested positive for bird flu antibodies, suggesting it had been exposed to the disease without being infected, the ministry said in a statement.

Asia’s fourth-largest economy has had four bird flu outbreaks in the past 10 years, without any cases of human infection reported.

Sales of chicken in one of Seoul’s largest markets dropped by more than half on average last month in the wake of the latest outbreak, according to a ministry official. No nationwide data is available.

South Korea’s first case of H5N8 bird flu - different from the strain that has caused human deaths elsewhere in Asia - was found on January 17 at a duck farm in North Jeolla province, around 300 km (186 miles) southwest of Seoul.

Some 28 poultry farms across the nation have been hit by the disease, the ministry said.

South Korea has been stepping up disinfection measures for migratory birds, the suspected source of the present outbreak, at 37 sites across the country. It also curbed the movement of some livestock workers in affected areas.

China has seen a wave of human H7N9 bird flu cases and deaths in 2014.