The two main types of salmonella which can affect cattle are salmonella Dublin and salmonella typhimurium. It usually manifests itself as diarrhoea and infected animals present as being very sick and usually dehydrated. In calves, this occurs mainly between two and eight weeks of age.

The infection is very contagious, with young calves at most risk. Old stock are also at risk. However, there is also a chance that the infection can be passed from cattle to humans.

Once an animal presents itself with an infection, the first step should be to isolate it to try to reduce the risk of spreading infection.

Salmonella Dublin is the most common form and is often introduced through brought-in cattle in the form of a carrier. Often, an outbreak can occur when a carrier animal becomes stressed and starts shedding into the environment.

The infection in dairy herds can also manifest itself in the form of abortion from months five to eight of pregnancy. In severe cases in calves, scour can cause damage to blood vessels at the edges of the feet, tail and ears.

Salmonella typhimurium can be spread by contaminated feed, vermin and birds. The main method of the spread of either disease is through the ingestion of contaminated faeces.

Vets also advise farmers to avoid feeding milk from clinically infected cows and to ensure that bedding, water troughs and feeding equipment are clean. Hot water should be used to clean feeders between feeding calves.

Calves should be bedded daily. Calves with strong and healthy immune systems are often better able to deal with the disease. You should ensure that calves eat adequate colostrum, at least 3litres within the first two hours of life.

If a problem does occur, it is vital that the farmer consults his/her vet to diagnose the problem and take corrective action. Vaccination may be required at herd level to control the disease in the long-term.