The Sahel corridor, stretching from Senegal to Chad, is traversed each year by millions of livestock as part of traditional transhumant movements. These seasonal migrations, essential to the pastoral economy, also serve as vectors for the cross-border spread of infectious diseases. A study coordinated by FAO and the World Organisation for Animal Health (WOAH) documents the scale of this phenomenon for the first time. Researchers tracked 1,200 herds equipped with GPS tracers across six Sahelian countries over two complete transhumance seasons. Samples collected at border crossing points revealed alarming rates of Extended-Spectrum Beta-Lactamase (ESBL)-producing Escherichia coli, with prevalence ranging from 35% in Senegal to 62% in Niger. Dr. Amadou Dicko, FAO Representative for West Africa, emphasized that "transhumance is a vital way of life for millions of people, but it requires appropriate health support." He presented a new regional cooperation framework that includes harmonized surveillance protocols, mobile veterinary checkpoints, and real-time epidemiological data sharing. This framework, endorsed by ECOWAS heads of state at the Lomé summit in January 2026, benefits from EUR 28 million in funding from the European Union and the African Development Bank. The first mobile checkpoints are expected to be operational by September 2026.