SFMS Veterinary Medicine Practice Test

In zebras, African Horse Sickness tends to be mild or subclinical, so mortality is typically low. Zebras often harbor the virus without severe disease, allowing them to serve as reservoir hosts that help maintain transmission cycles in an area. The virus is spread by Culicoides midges, so infected zebras can persist in the population even when horses are not present or are less affected. In contrast, horses can experience severe, often fatal forms of the disease, which is why the overall impact on zebras is much less dramatic. This combination of subclinical infection and reservoir status explains why the statement about low mortality in zebras is the true one.