Cows & Salmonella

Salmonella is a significant cattle disease, according to the website of the Animal Disease Diagnostic Laboratory at Purdue University. The disease is also transmissible to humans through contaminated milk or meat. The disease is estimated to cause 1,000,000 illnesses and up to 500 human deaths each year in the United States. Control of salmonella in cattle herds can reduce the incidence of human disease.

  1. Symptoms

    • Cows with a salmonella infection may have no observable symptoms. These animals are considered to be "symptomless carriers" according to Cornell University. Other cattle may have symptoms such as dehydration, diarrhea, fever and breathing difficulties. Latent carrier cattle have symptoms but do not pass the salmonella bacteria from their bodies while active carriers pass salmonella in feces and milk.

    Diagnosis

    • Diagnosis is usually accomplished by culturing the bacteria from samples of blood, body tissue or feces. Local laboratories can conduct the tests, but final confirmation on any salmonella issues is conducted by the National Veterinary Services Laboratory in Ames, Iowa.

    Spread of Salmonella at the Farm

    • Salmonella spreads among cattle by consumption of feed or water contaminated by the feces of infected animals. Sanitation of feed bunks, water troughs and forage handling equipment lowers the possibility of the spread of salmonella within the cattle herd. Newborn calves and cows that have just given birth should be particularly protected.

    Salmonella Bacteria

    • Salmonella bacteria can survive in for up to 200 days in pastureland and 251 days in garden soil, according to Cornell University. Its ability to survive in liquid manure varies from about four weeks to nearly a year depending on the variety of the bacteria. Effective farm sanitation programs need to be continuous.

    Human Risk

    • Farm workers who handle sick cattle and calves are at risk of contracting salmonella. Poor personal hygiene and contact with animal saliva and manure also contribute to human incidence of the disease among the farm and ranch workers. Consumers who drink raw milk or eat fresh cheese made from raw milk are also at risk of contracting salmonella.