Over the past several years, swine dysentery, or bloody scours, has begun to re-emerge in the Midwest as well as Canadian operations, according to an Iowa State University publication.

In 2005, only three samples were found positive by the Iowa State University Veterinary Diagnostic Laboratory. By 2010, the number had grown to 84.

Swine dysentery, which had largely disappeared during the 1990s, poses several challenges to pigs and producers alike. Once established in facilities the disease is expensive to treat and difficult to remove.

Symptoms of swine dysentery (SD), which is caused by Brachyspira hyodysenteriae, include soft, watery feces varying in color (gray, yellow or red) and often containing mucus or blood, according to ‘Bloody Scours (swine dysentery) A costly re-emerging disease that is preventable.’ The publication was published by Iowa State University Extension and Iowa Pork Producers Association.

Clinical signs of SD may spread slowly within a barn or rapidly depending on the exposure dosage. Groups of pigs with the disease will grow unevenly which leads to variation in weights.

To make things more difficult, the disease may be present without symptoms. “Swine dysentery can be difficult to diagnose because there may not be diarrhea or mortality associated with infection,” says Hank Harris, DVM, Harrisvaccines.   “That can be a particular problem for wean-to-finish operations.”

Infected pigs and their feces are primary sources of infection. Infected transport vehicles as well as manure storage facilities and handling equipment can also transmit the disease, since the causative organism can survive for long periods in feces-contaminated environments. Plus, mice can carry the causative organism for a year after infected pigs are removed. “There’s no question that mice are a reservoir of infection,” Harris says.

Strict biosecurity is key to preventing contamination of facilities with SD. Avoiding contact with infected animals and other materials is crucial in preventing the disease. Your veterinarian can help in developing an effective SD prevention program.

For information on receiving a copy of the SD booklet, call (515) 225-7675 or email info@iowapork.org.

Read more about swine dysentery.