Asiatic redwater: The role of vaccination and disease reporting

Redwater is an important disease in South Africa, and is responsible for significant losses and rapid onset of deaths among cattle. Its continual spread into new regions poses a serious threat to livestock health and productivity.

- Christal-Lize Muller

Asiatic redwater is caused by Babesia bovis and is transmitted by the Asian blue tick, Rhipicephalus (Boophilus) microplus. African redwater, on the other hand, is caused by Babesia bigemina and is mainly transmitted by the blue ticks R. (B.) decoloratus and R. (B.) microplus.

African redwater has a slower progression. Infected cattle may develop a high fever (above 40°C), lethargy, loss of appetite, pale mucous membranes (indicative of anaemia), jaundice, and red-coloured urine over several days. With prompt diagnosis, early treatment can be effective.

Asiatic redwater, however, is more aggressive. Animals may die without any obvious signs; however, in some cases, red urine is absent, while in others neurological signs such as aggression are seen. When multiple animals in a herd die suddenly and Asiatic redwater is confirmed, the entire herd should be treated preventively.

Disease trends

According to animal disease reports released in January 2025, December 2024 was an exceptionally dry month. In contrast, January 2025 saw high rainfall figures across large parts of the summer rainfall region, including the northern areas (Limpopo, Gauteng and northern Free State), eastern regions (Mpumalanga and KwaZulu-Natal), and western areas.

Tick populations tend to increase sharply following good rainfall, particularly when these conditions are followed by hot, dry weather. Since November 2025, many areas within the summer rainfall region have received good rains, which is expected to result in high tick numbers as temperatures rise.