6 Oct 2018
Diarrhoea or calf scour can be a major cause of poor growth and calf mortality in many dairy herds.
The incidence and severity of disease is highly dependent upon the level of colostral protection that a calf receives within the first six hours of life (Fig 1). Indeed, it is generally recommended that calves receive three litres within the first 2 hours of life. 1,2,3; first milk, within two hours, three litres!
The most important causes of calf diarrhoea are rota- and corona-viruses but on a small number of dairy farms Salmonella species, such as Salmonella Dublin and Salmonella typhimurium, can be a major problem. However, it is essential to appreciate that most outbreaks of calf diarrhoea are caused by viruses. Fluid therapy is the most effective treatment strategy; antibiotics are rarely indicated and their use is contrary to the responsible use of antibiotics in agriculture.
As with all animal diseases prevention is better than cure and an effective veterinary herd health plan is essential for all dairy herds to maintain health and prevent costly diseases. Effective vaccines are available against the most important infectious causes of calf diarrhoea but such a prevention strategy will only work if calves receive adequate volumes of good quality colostrum within few hours of birth, and in the case of viral causes, continue to receive stored colostrum from vaccinated cows for the first two weeks of life.