Three million pigs may have been lost to porcine epidemic diarrhea virus (PEDV) during 2013, according to some estimates, says Bob Thaler, South Dakota State University (SDSU) Extension swine specialist.
“The first cases were reported this May, and as of Dec. 1, 2013, there are 1,512 cases in 20 states in the United States,” Thaler says. “The disconcerting news is that this is an increase of 140 new locations from the week before, which is the largest one-week jump in cases.”
While South Dakota has only two reported cases, Thaler says multiple cases have been reported in Iowa and Minnesota, with Nebraska reporting its first cases the end of December.
“Outbreaks of PEDV can be devastating. There is 100% mortality in newborn pigs, and this typically creates a five-week hole in pigflow because there are no pigs to wean,”Thaler says. “Pigs in the early nursery phase don't experience the high death loss, but it does cause severe diarrhea so many pigs are stunted and nursery performance suffers.”
As pigs get older and their own immune system becomes functional, Thaler says there is little to no death loss, and most pigs experience just a one-week lag in growth performance.
“One of the good things about PEDV is it appears that the virus itself is not an airborne threat,” he says. “However, it is very easily transmitted by manure and if a virus-contaminated piece of manure were to be small enough to get aerosolized, then PEDV could travel in the air.”
Thaler says preventing infected manure from getting on your farm is the best way to prevent PEDV.
“Unfortunately, PEDV is an extremely infective virus and it only takes a minute amount to cause an outbreak,” he says. “PEDV can live in manure slurry up to 14 days at room temperature, and more than 28 days in cold slurry, so it is not affected by the cold. It can also live in feed up to one week,” he says.
The biggest threat to pork producers is when they take their pigs to market. Packing plants and buying stations are great commingling places for disease.
Before getting out of the cab, producers need to put on a pair of disposable boots and then get the pigs unloaded. Before getting back into the cab when done, they need to take off and discard the boots immediately before entering the cab.
“Even a small chunk of manure on the floor mat means disaster,” Thaler says.
He adds that many producers routinely go to truck washes after unloading hogs to clean out their trailer. While this is a good idea, Thaler reminds hog producers that truck washes are also another commingling place where PEDV is prevalent.
“Any manure that splashes up on the truck, tires, or boots during the cleaning process probably has the PED virus in it. After cleaning the trailer at a truck wash, it needs to be sprayed with a disinfectant and allowed to dry,” he says.
When done properly, drying and disinfecting will take care of both PRRS and PEDV. Thaler also encourages producers to visit with their veterinarian about which disinfectants are the most effective.
“If a clean and disinfected truck and trailer can be dried at 160 degrees F for 10 minutes, the virus should be gone,” he says. “If they are dried at room temperature, it'll take one week to kill the virus.”
He adds that recent research shows that convenience stores are also a great commingling place for PEDV.
“In a study in Iowa, the floors of over 50 different convenience stores were swabbed and all tested positive for the PED virus,” he says. “If a person goes into the store for coffee and a roll after selling a load of hogs, they risk picking up the PED virus on their shoes, which then could infect their whole herd at home.”
Therefore, Thaler suggests bypassing the convenience stores if producers plan to visit the unit when they get home - or at least make sure they change shoes before going back into the operation.
While PEDV is a devastating disease for swine operations, Thaler says strict adherence to biosecurity protocols can dramatically decrease the chances of getting it.
“Everybody involved with the operation needs to buy into the program, and that will also reduce the risk of bringing in other diseases like porcine reproductive and respiratory syndrome (PRRS),” he says.
For more information, contact Bob Thaler, SDSU Extension swine specialist, (605) 688-5435; Russ Daly, SDSU Extension veterinarian, (605) 688-5172 or Ashley Gelderman, SDSU Extension swine field specialist, (605) 782-3290.
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