The presence and severity of symptoms depends on the infecting dose. Typically there is watery diarrhoea for about ten days, possibly leading to dehydration, with abdominal pain and low-grade fever. Septicemia and abscess formation are rare. Subclinical infection is common and many animals may be intermittent or persistent carriers. However, cows may suffer with fever, diarrhoea and abortion.
Calves undergo epizootic outbreaks of diarrhoea with high mortality.
In pigs, fever and diarrhoea are less common than in cattle. Infected sheep, goats and poultry usually show no signs of infection. Isolate salmonella from feces and suspected foods using selective media followed by serotyping and, if appropriate, phage typing. Culture feces, postmortem tissues and foods of animal origin. Serological tests are of limited value as many noninfected animals have titers from past infections.