South Africa’s Department of Agriculture, Forestry, and Fisheries (DAFF) is urging and encouraging horse owners to vaccinate their animals annually in an effort to curb the impact of African horse sickness (AHS).
AHS is a controlled animal disease in South Africa in terms of the Animal Diseases Act, 1984 (Act No. 35 of 1984) and all suspected or confirmed cases must be reported to the nearest state veterinarian.
The disease is transmitted by Culicoides midges. it is not by spread via horse to horse contact. Favorable climatic conditions (i.e., summer rainfall) can increase the breeding and spread of the Culicoides vector. Heavy rains preceded by a prolonged dry spell favor the occurrence of epidemics. The number of outbreaks generally declines after the first frost and normally the disease occurrence drops abruptly in May.
Owners are encouraged to vaccinate their animals before the start of the rainy season to limit the impact of the disease. As an extra measure, it is advisable to stable horses for at least two hours before sunset and keep them stabled for at least two hours after sunrise as this is the period when Culicoides are most active and known to be feeding. Culicoides also colonize around stagnant water sources, so efforts should be made to prevent water pooling and to move animals away from water sources, such as ponds or lakes.
All horses in the country (except in the AHS free and surveillance zones in the Western Cape) should to be vaccinated annually using a registered vaccine at the cost of the owner. Currently, the AHS vaccine from Onderstepoort Biological Products is the only registered vac