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Salmonella: reduce your risk

Salmonellosis in cattle

Salmonella disease is a growing concern for dairies. Cattle of all ages can suffer from a variety of disease symptoms. Even more alarming, some animals show no signs at all.


Check out the proactive approach used by SRP technology to prevent Escherichia coli O157 and Salmonella Newport bacteria from gathering the iron they need to survive.

How bad is Salmonella on dairies?

Producers and veterinarians talk about how quickly things can go bad when Salmonella disease hits a dairy. Find out what signs to look for.

Salmonella can spread in many ways.

Veterinarians tell us to be suspicious of everything that moves onto a dairy from somewhere else, and everything that moves around on the dairy. It's easy for Salmonella to arrive and spread.

Salmonella is a costly disease.

Some of the costs of Salmonella disease are obvious, such as loss of life. Some are hidden, like chronic loss of productivity. Two veterinarians and a producer share their experiences.

Start Salmonella protection with the most susceptible cattle.

Which animals are at the greatest risk of Salmonella disease? This is the place to start with changes in management and vaccination protocols.

How do you control Salmonella?

Producers and veterinarians talk about controlling Salmonella with management — sanitation is a big concern — and vaccination.

Most Salmonella infections are subclinical.

Like an iceberg, many Salmonella infections are hidden below the surface. Subclinical cases can outnumber clinical cases and can rob your dairy of performance.

How Salmonella spreads on the dairy.

Animals that are infected either clinically or subclinically can spread the disease. Salmonella even becomes a part of the environment, from which it can be transmitted to cattle.


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  • Salmonella is an industry-wide problem

    Salmonella in cattle can be a devastating problem to the dairy and beef industries and is a significant foodborne pathogen. Incidence also is on the rise, according to data from the National Animal Health Monitoring System (NAHMS) Salmonella study by the U.S. Department of Agriculture:1,2

    • In the 2007 NAHMS Salmonella study, 48 percent of all dairies were found to be infected with Salmonella, nearly twice as many as in 1996.

    • Since 1996, the percentage of dairy cows infected with Salmonella has more than doubled to 13.7 percent.

    • In the 1999 NAHMS study, 50 percent of feedlots were infected and 22 percent of feedlot pens had a positive fecal sample for Salmonella. In this study, Salmonella Newport was one of the five most common serotypes recovered

    Salmonella in cattle can be spread from farm to farm in a number of ways meaning producers need to be on alert for this disease especially if Salmonella is prevalent in cattle on neighboring farms.


  • Salmonella can be undetectable

    Salmonella in cattle will not always display clinical signs and therefore goes unnoticed. In fact, subclinical Salmonella infections usually are unseen, but nonetheless can reduce milk production and herd performance.3 Nearly half of all U.S. dairies and feedlots had a positive test result for Salmonella in their cattle.1,2

    Subclinical Salmonella disease is a serious threat to cattle producers because it can lead to animals that are sick and shedding but show no visible signs of salmonellosis. In fact, the majority of Salmonella infections in dairy and beef herds over a period of time are subclinical. Some cattle can shed Salmonella in their manure for over a year, and shedding frequently lasts well beyond the typical length of clinical signs of disease in sick cattle.4 Once the disease makes it into a herd, it can be devastating to cattle health and performance.

    The harmful effects of subclinical Salmonella in cattle can often be just as severe as clinical disease. Salmonellosis can escalate rapidly in young calves, causing septicemia, fever and even sudden death before other more obvious clinical signs become apparent.5

  • Salmonella can rob a herd of performance

    Salmonella in cattle can be a very costly disease to dairy and beef producers. The costs of salmonellosis add up in a number of ways:6

    • Mortality

    • Reduced milk production

    • Abortion

    • Weight loss

    • Poor feed efficiency

    • Treatment expenses

    Economic losses also may be realized as a result of poor reproductive performance that can lead to prolonged lactations, excessive body condition in late lactation, and increased metabolic disease at calving, which then may increase the risk of salmonellosis in postpartum cows and calves.

  • Salmonella spreads in many ways

    It's not hard for Salmonella to come onto a cattle operation.

    There are many routes Salmonella transmission can take and many potential sources of bacterial contamination6,7

    • Purchased or new cattle

    • Contaminated feed or water

    • Contaminated loaders or feeding equipment

    • Weight loss

    • Wildlife such as flies, rodents and birds

    • Visitor or employee traffic

    Salmonellosis can be fast-acting and fatal, or can exist at a subclinical level with no outward signs of illness. Salmonella in dairy and beef operations can be easily spread among livestock and into the production environment by healthy-appearing carrier animals, infected animals, rodents and environmental contamination. The shedding of Salmonella increases the risk of bacteria transmission from the feces of infected animals to mouths of susceptible animals.

    Widespread contamination of a farm can result from Salmonella shedding, and the pathogen can survive for long periods of time in suitable conditions outside the bodies of cattle (in water or on bottles, buckets, equipment, etc.) making it difficult to control.4

  • 1 National Animal Health Monitoring System. Salmonella and Campylobacter on U.S. dairy operations, 1996-2007. APHIS Info Sheet, July 2009, #N562.0709.

    2 National Animal Health Monitoring System. Salmonella in United States feedlots. (Feedlot ‘99) APHIS Info Sheet, October 2001, #N346.1001.

    3 Hermesch DR, Thomson DU, Loneragan GH, Renter DR, White BJ. Effects of a commercially available vaccine against Salmonella enterica serotype Newport on milk production, somatic cell count, and shedding of Salmonella organisms in female dairy cattle with no clinical signs of salmonellosis. AJVR 2008;69(9):1229-1234.

    4 Cummings KJ, Warnick LD, Alexander KA, et al. The duration of fecal Salmonella shedding following clinical disease among dairy cattle in the northeastern USA. Preventive Vet Med 2009; 92:134-139.

    5 Mohler VL, Izzo MM, House JK. Salmonella in calves. Vet Clin Food Anim 2009; 25:37-54.

    6 Clark S, Thacker L. (2004). Salmonella newport - an emerging disease in dairy cattle. Purdue Newsletters 2004; http://www.addl.purdue.edu/newsletters/2004/summer/salmnewp.htm, accessed June 2011.

    7 Cummings KJ, Warnick LD, Alexander KA, et al. The incidence of salmonellosis among dairy herds in the northeastern United States. J Dairy Sci 2009; 92:3766-3774.

    8 Brad Smith personal communications

    9 Bertoldo J. Salmonella – A very successful opportunist. Cornell University AgFocus 2006; http://www.nwnyteam.org/AgFocus2006/Jan/AgFoc0106Salmonella.htm, accessed June 2011. 

    10 Data on file, Epitopix, LLC. Study Report No. N-0005-136-142, Pfizer Inc..

    11 Loneragan, GH, et al. Salmonella in Cull Dairy Cattle of the Texas High Plains. 89th Annual Meeting of the Conference of Research Workers in Animal Diseases, Dec. 7-9, 2008, Chicago, Ill.

*This product license is conditional. Efficacy and potency test studies are in progress.

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