Porcine Epidemic Diarrhea – Don’t bring it home

Swine herds have no immunity to new virus – Strict biosecurity is best method for prevention and control of PED.

An outbreak of Porcine Epidemic Diarrhea (PED) has recently been confirmed in Indiana and Iowa with suspect cases in Illinois and Colorado. This is a new virus to Canada and the United States so it is expected that there is no immunity in North American swine herds. PED has been found in swine herds in Europe and Asia starting in the early 1980s. PED is a production disease, affecting the growth and health of the animal. It is not zoonotic, meaning humans and other species can’t catch it from direct contact with pigs. This disease is also not a food safety concern and all pork products remain safe for consumption.

This disease is similar to TGE (Transmissible Gastroenteritis) and causes severe watery diarrhea in pigs and vomiting. The strain of PED virus found in the United States is 99 percent homologous (similar) to the Asian strain which remains highly contagious. Mortality in piglets is high (up to 80 percent) due to dehydration. Mortality in sows, nursery and finisher pigs is lower with clinical signs of fever, vomiting and diarrhea. Sudden death may occur, likely due to twisted gut following vomiting. Swine herds with confirmed PED in the United States were likely exposed to the virus 5-8 days prior to exhibiting clinical signs. The clinical expression can move through the affected barn unit rapidly, typically within 12-36 hours. Normally, producers will not see a difference in clinical signs between TGE and PED outbreaks. However, the PED virus survives well in high temperatures and is seen predominantly during the summer season. Confirmation of PED infections requires sampling and testing.

There is no treatment or effective vaccine available for PED so an emphasis should be made on prevention and control.

Although all transmission routes of PED have not been confirmed, it is suspected to be transmitted via infected pigs, transportation vessels and contaminated fomites, such as clothing, footwear and equipment. In order to help protect your herd from possible infections, review your biosecurity plans and strategies to increase biosecurity protocols. These strategies would include washing and disinfection protocols for all trucks returning from market, change of footwear, change of outerwear such as coveralls and washing hands prior to entry to the barns where pigs are housed.

The transmission of PED is fecal-oral route from infected pigs to naïve pigs. As this is a new virus to the United States, we can expect that most pigs are naïve. In fact, a small amount of virus transported on coveralls or footwear and worn into your farm can infect your herd. Ensure that you are changing footwear and coveralls when coming from a public pig area back to your farm. Other biosecurity measures include limiting visitors onto the farm site and washing and disinfecting transporting equipment with a 6 percent chlorine solution at a 1:32 ratio. Also ensure that other fomites such as equipment is clean and disinfected prior to entry of your barn. Limit movement of equipment such as shovels, snares and syringes to one location. Incoming stock should be held offsite for a minimum of 28 days.

In the event that PED circulates on your farm, suckling pigs should have free access to water to help decrease dehydration. Immunity can only be developed through exposure and many producers will try to eradicate the virus through blanket exposure to all pigs, especially in farrowing units through feedback procedures. However, feedback procedures have drawbacks in that it also spreads other herd viruses. Please consult with your herd health advisor prior to implementation of a feedback program.

Sanitary and quarantine measures can help to slow the spread of the virus. Introduction of new stock should also be suspended during an outbreak or coordinated such that incoming gilts are exposed at the same time as the rest of the herd.

Contact your veterinarian if you suspect PED or TGE to develop testing and immune response strategies. PED is not a reportable disease although this is the first time that is has been detected in the United States. PED is labeled a transboundary disease by the USDA.

The USDA is working with various state laboratories to build testing capacity to detect the PED virus. Presently, Iowa State Veterinary Diagnostic Laboratory has the testing equipment available. Other Midwest labs are developing tests as well. If you suspect PED on your farm, please contact your veterinarian or Iowa State Veterinary Diagnostic Laboratory to determine the best laboratory services for your location. Producers and veterinarians looking to submit samples to the Iowa State University Laboratory should collect samples from pigs expressing clinical signs of the disease. Fresh samples from the small intestine and colon, along with feces collections are preferred.

If you suspect clinical signs or have questions please contact your herd veterinarian. Michigan State University Extension is also a resource for producers. More information can be found by contacting Dr. Madonna Benjamin, Extension swine veterinarian at gemus@cvm.msu.edu or (517) 614-8875 or Beth Ferry, Pork Educator at franzeli@msu.edu or (269) 445-4438. More information will be posted on the MSU Extension News website’s pork page at as it becomes available.

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