The U.S. Department of Agriculture today enlisted swine veterinarians to further assist in the tracking of porcine epidemic diarrhea virus (PEDv), which has devastated pig farms in up to 30 states. New USDA guidelines mandate the reporting of PEDv cases and documenting the movement of pigs, vehicles and other equipment that leave farms and other places where the disease has been found. PEDv and the newly identified Swine Delta Coronavirus reportedly have killed at least 4 million swine, mostly piglets, in the United States and Canada since PEDv emerged in May 2013. The diseases pose no threat to people or pork products, authorities stated. "USDA has been working closely with the pork industry and our state and federal partners to solve this problem," Agriculture Secretary Tom Vilsack said. "Together, we have established testing protocols, sequenced the virus and are investigating how the virus is transmitted. "Today's actions will help identify gaps in biosecurity and help us as we work together to stop the spread of these diseases and the damage caused to producers, industry and, ultimately, consumers," he added. The monitoring and control program is a work in progress. USDA reported that swine veterinarians can help the agency determine: How often to test herds and what samples to collect. What biosecurity procedures to require. What herd-level control procedures to require. When to release a herd from the monitoring program. The monitoring has the support of the American Veterinary Medical Association. "While we realize mandatory reporting will impact industry in the short term, we believe this action by the USDA will be beneficial in the long run to both the animals and the industry," said Kristi Henderson, DVM, the organization's assistant director for the Scientific Activities Division. "Such reporting will help veterinarians, animal health authorities and the industry in identifying and containing disease sources more quickly and thereby enhancing disease control," Dr. Henderson said. Spread through feces, PEDv strikes pigs after a two- to four-day incubation period. Infected animals suffer severe diarrhea and vomiting, and the mortality rate is 50 to 100 percent in young pigs. Older pigs fare better. Stringent sanitization practices have been found to control and kill the virus. Common disinfectants such as bleach and Virkon S work well, and heating trailers to 160 degrees Fahrenheit for 10 minutes may inactivate PEDv, according to the American Association of Swine Veterinarians. The transition from winter to summer may bring a downturn in PEDv cases, said the swine association's executive director, Tom Burkgren, DVM, MBA. "It's a virus that likes the cool, cold weather better than the warm weather,? Dr. Burkgren said. "The number of cases really rose in January and February, and March plateaued a little bit. "We don't think it's going to go away completely when it warms up,? he added. "We'll still have cases. Come next November, December, there will be a lot of veterinarians and producers holding their breath, hoping it doesn?t come back with a vengeance." Besides decontamination, another preventive is a prescription vaccine, iPED+, developed by Harrisvaccines of Ames, Iowa. The company reported shipping 1.4 million doses to producers as of mid-March. The disease can spread quickly through herds. A Plainwell, Mich., producer told a television station this week that he lost 5,000 pigs to PEDv in just 10 days. The National Animal Health Laboratory Network reported that PEDv had been found in 29 states and that Virginia likely will become the 30th state affected.