A fourth African swine fever (ASF) outbreak had been reported in the Heilbron area of the Free State this month, the Department of Agriculture, Forestry and Fisheries (Daff) said on Monday.
This follows three previous outbreaks in the North West, Mpumalanga and Gauteng last month.
According Daff, all four outbreaks occurred outside of the controlled ASF area of South Africa but have been reported to the World Organisation for Animal Health.
Affected areas have been placed under quarantine and provincial veterinary services have responded accordingly.
ASF has spread worldwide, crippling markets. China has reported outbreaks in nine provinces.