Salmonellosis

Salmonellosis is a disease that occurs worldwide and can cause disease in most warm-blooded mammals. In cattle, the most common types of Salmonella are S. dublin, S. typhimurium, and S. newport. The prevalence of Salmonella in cattle is low. Outbreaks of disease in cattle are rare. Sources of the bacteria for cattle include carrier animals, contaminated feeds and water, sewage or slurry, rodents, birds, man, wild animals and pets, and unsterilized animal and fish by-products used in feed and fertilizers. In cattle, the concern of Salmonella is disease in cattle and infection of humans through direct contact with infected cattle or through fecal contaminated food, equipment, facilities, and environment. Salmonella can remain viable on pasture, soil, water, and feces for long periods of time.

Cattle become infected most commonly through ingestion of contaminated feed or direct spread among animals. Some infected cattle show no clinical signs and are carriers of the bacteria. Other cattle may have a septicemia with fever and depression, diarrhea, wasting (thin), abortion, or dry gangrene of extremities (ear tips, tail tip, lower limbs). Occasionally sudden deaths are the first sign of a problem in a herd. Treatment for cattle includes isolation, fluids, astringents, and antibiotics. Prevention and control of outbreaks includes vaccination (vaccination gives mixed results so discuss this with your veterinarian), isolation of sick animals, sanitation (avoid use of hospital area for processing newly arrived cattle), personal hygiene, restriction of cattle, pet and human movements, pest control, and manure management. Manure from pens and barns should be placed on crops and not on pastures, because Salmonella do not survive silage or hay making. Incoming feeds and byproducts should be properly sterilized and certified free of Salmonella. Grain and hay should be fed off of the ground. Feed storage areas should be closed to prevent access to pets, wild birds, and other potential carrier animals. Carcasses should be burned or buried quickly to avoid spread of the disease among wildlife and pets and contamination of the environment. In some provinces, clinical salmonellosis is a reportable disease. Therefore, contact your local veterinarian to determine the appropriate course of action. In some provinces, infected animals can not be sold without informing the purchaser of their status. This would include informing the packer prior to shipment for slaughter.

To prevent transmission to family and workers, personal hygiene should be emphasized. To prevent foodborne disease, during processing, fecal contamination of beef must be prevented. As well, humans that are carriers should not handle food. Meat should be properly refrigerated and frozen and cooked to 160 F or 70 C. Only pasteurized milk and purified water should be consumed. Disposal of sewage should be effective.