An outbreak of African horse sickness (AHS) detected in late March in South Africa has killed 300 horses, according to a Pro-MED report. African horse sickness is a lethal virus spread by the Culicoides bolitinos midge, a species of small fly. Although AHS is endemic to all parts of Africa (except the Western Cape), rain has increased the midge population.

The outbreak began in the Underberg-Loteni district. Since March 31, many equine sporting events were cancelled, and a voluntary transportation ban was established to prevent the disease’s spread.

Many horse owners cannot afford to vaccinate their herds against AHS. Blood samples have been sent to the Equine Research Centres at Onderstepoort and Allerton to determine the virus strain responsible for the outbreak, and which serotype vaccination to use.

Clinical signs for AHS include fever, difficulty breathing, swelling above the eyes or of the entire head, coughing, nasal discharge, excess salivation, sweating, restlessness, lack of energy, and general stress and lethargy due to edema (fluid swelling) around the heart and lungs