African Horse Sickness Outbreak Kills 300 Horses in South Africa

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.

The death rate in affected horses is high. According to the Office International des Epizooties (the World Organisation for Animal Health), the mortality rate is 70-95%. There is no cure for the disease, and medicine to treat the clinical signs is very costly. Horses under treatment must be on complete stall rest before gradually returning to activity.

The National Department of Agriculture offered recommendations for control of the disease, which can be read in article #4287 online.

About the Author

Sarah Evers Conrad

Sarah Evers Conrad has a bachelor’s of arts in journalism and equine science from Western Kentucky University. As a lifelong horse lover and equestrian, Conrad started her career at The Horse: Your Guide to Equine Health Care magazine. She has also worked for the United States Equestrian Federation as the managing editor of Equestrian magazine and director of e-communications and served as content manager/travel writer for a Caribbean travel agency. When she isn’t freelancing, Conrad spends her free time enjoying her family, reading, practicing photography, traveling, crocheting, and being around animals in her Lexington, Kentucky, home.

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