Four sentinel herds comprising cattle, sheep and goats were established at various localities in Saudi
Arabia. Maternal bluetongue antibodies were detected in all four sentinel herds but disappeared in
4- 6 months, immediately followed by seroconversion in all. Serological results indicated that the animals
were recently exposed to BT virus serotypes 10, 12, 15 and 20. The epidemiology of the disease
in Saudi Arabia is discussed.