Twelve cases of African horse sickness (AHS) have been confirmed in the Western Cape region of South Africa, according to a report from the South African-based news website Eye Witness News.

The cases in the Western Cape follow an outbreak of more than 90 cases in other regions of South Africa. Movement into the Western Cape had been restricted in an attempt to control disease spread.

On March 4 authorities halted the transportation of all horses, ponies, donkeys, mules, and zebras in the Western Cape district of Malmesbury, where the cases were suspected and later confirmed, according to Eye Witness News.

African horse sickness is a fatal viral disease spread by Culicoides–tiny, blood-sucking insects–that can affect horses, mules, and donkeys, as well as dogs and camels. Horses are most susceptible to AHS, with a 75-90% mortality rate. A vaccine is available, but no effective treatment methods exist for infected horses. For survivors, recovery is slow