A number of villagers living in Dongtun village in Henan Province awoke Monday to find their pigs and dogs dead or dying, Beijing's Global Times reported Thursday.
Villagers described pigs running around foaming at the mouth and dogs suddenly barking before dropping dead, the Dahe Daily reported.
A nearby chemical plant, which manufactures fluorine products, was shut down in response to the incident, the Times reported.
"The factory has been operating for more than 10 years and the foul air has always made the villagers furious and worried about their health," a village doctor identified only as Kou said.
Kou said some villagers came to her clinic complaining of dizziness, but their vitals checked out normally.
Local authorities called in health practitioners to test the health of local residents, the air and soil, and no abnormalities were found, the doctor said.
A press officer with the Yanshi City Party Committee said an investigation into the cause of the mass animal deaths was launched.