This follows after outbreaks were registered in the North West, Mpumalanga and Gauteng in April.
According to the departmental spokesperson, Khaye Nkwanyana, all four outbreaks occurred outside of the ASF controlled area of South Africa and have been reported to the World Organisation for Animal Health.
He says the affected areas have been placed under quarantine and provincial veterinary services are applying the necessary disease control measures.
Nkwanyana added that veterinary services, together with the industry, were conducting follow-up investigations to trace the origin of the disease and to identify other farms that may possibly be affected.
He said it would be advisable to buy pigs only from reputable owners and insist on a health verification by their veterinarian. He says they fear that the outbreak might spread to other parts of the country.
Nkwanyana requested farmers to be vigilant and to report any sudden illnesses and deaths of their pigs to the local state veterinarian.
OFM News/Michael Tlhakudi