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The No.1 health problem facing grow/finish pigs

Ileitis, a gastrointestinal disease, is a common and costly problem. According to the U.S. Department of Agriculture’s Animal and Plant Health Inspection Service, it is the No.1 health problem in growing pigs, as evidenced by both clinical and subclinical forms. The disease is also known as porcine proliferative enteropathy and is caused by the bacterium Lawsonia intracellularis.

There are three forms of the disease – acute, chronic and subclinical. Nearly 42 percent of grow/finish operations reported clinical ileitis and nearly 94 percent of herds with no clinical signs were found to have subclinical ileitis.1,2

Ileitis is known to cause thickening of the small intestine wall. Intestinal lesions can also form, affecting pigs’ growth and development.  

1. USDA. 2007. Swine 2006, Part II: Reference of Swine Health and Health Management Practices in the United States, 2006. USDA:APHIS:VS, CEAH. Fort Collins, CO. #N479.1207

2. Armbruster GA, Deen J, Gebhart CJ, Pelger GA, Keffaber KK, Parks CW. Review of Lawsonia intracellularis seroprevalence screening in the United States, June 2003 to July 2006, in Proceedings. 38th Annu Meet Amer Assoc Swine Vet, 2007.

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  •  The signs of ileitis are similar to other enteric diseases, which can make diagnosis difficult.

    Subclinical ileitis – No apparent clinical signs of the disease are present, however it has been reported to slash average daily gain by 38 percent and feed efficiency by 27 percent.1 Stress, from things like weather and moving or commingling pigs, may cause the disease to elevate to clinical ileitis.  

    Chronic ileitis – Typically occurs between six and 20 weeks of age and results in soft, watery and/or pasty diarrhea, and poor and uneven growth rate among pigs.

    Acute ileitis – Usually affects pigs in the finishing stage and can cause bloody or black diarrhea, weakness and depression, and occasionally, sudden death.   

    A major sign that a pig is infected with ileitis is failure to grow even with normal food intake. Ileitis can cause proliferation of the immature intestinal epithelium cells. Necrosis of these fast growing cells affects feed efficiency because nutrients are not absorbed properly. There may also be a decrease in water intake.

     Disease Transmission

    This disease is primarily transmitted through fecal shedding and has a high transmission rate. Even subclinically-infected pigs can shed the organism.1 Pigs can shed the organism for up to 12 weeks after clinical signs have abated. 

    1. Paradis MA, McKay RI, Wilson JB, Vessie GH, Winkelman NL, Gebhart CJ. Subclinical ileitis produced by sequential dilutions of Lawsonia intracellularis in a mucosal homogenate challenge model, in Proceedings. 36th Annu Meet Amer Assoc Swine Vet, 2005.

    2. Guedes R. Update on epidemiology and diagnosis of porcine proliferative enteropathy. J Swine Health Prod. 2004;12(3):134-138.
  • Ileitis can be diagnosed through post mortem or ante mortem testing. Fortunately, tools for diagnosing ileitis exposure and infection have become more readily available in the past few years.  

    STOMP Plus®

    Zoetis offers STOMP Plus – a diagnostic program to help pinpoint what diseases are occurring, as well as the level and timing of infection, so control programs can be implemented when they will do the most good. The program involves a combination of serology and fecal PCR testing. Contact your veterinarian or Zoetis representative if you are interested in testing your herd.

  • LINCOMIX® Feed Medication is approved to control ileitis. It offers zero-day U.S. withdrawal at all feeding levels and has no weight restrictions. Medication timing is critical to minimize the disease load and keep pigs from developing lesions and significant clinical signs. In addition to medication, employ biosecurity and sanitation measures to minimize bacteria spread.

  • Ileitis can cause major economic devastation if not controlled properly. Due to decreased average daily gain, poor feed efficiency, mortality, culls and days to market, the economic impact of this disease is estimated at $51.6 million.1

    1. Holtkamp D, Rotto H, Garcia R. The economic cost of major health challenges in large U.S. swine production systems, in Proceedings. 38th Annu Meet Amer Assoc Swine Vet, 2007.



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