Mike Salter runs Outagamie County's largest pig farm with about 400 swine. Lately he's paid a lot of attention to what's known as the PED virus, according to WBAY.

"This is serious in pigs and the number of baby pigs that are being lost are going to start being felt now," said Mr Salter.

Since first detected in the U-S last April, its estimated four million pigs have died from PED, which causes diarrhea, vomiting and severe dehydration in hogs. Babies are the most susceptible.

"The mothering pigs would have the babies and there's a 100-percent death loss within the first ten days if you have it on your farm," said Mr Salter, who also serves as Outagamie County Farm Bureau President.

Mr Salter said the disease is spread by pigs co-mingling, as well as people coming in contact with pig manure.

"You get it on our boots, they've tested, it's into hardware stores, it's on gas station counters, so it just spreads by sticking to people."

Right now, Wisconsin has six confirmed cases of the PED virus on farms, and in an effort to protect the state's pork industry, the state veterinarian issued a ban yesterday on all spring weigh-ins for pigs destined for county fairs this summer.

"It's a big deal to a lot of kids," said Mr Salter.

Mr Salter sits on the Outagamie County Fair Board and says more than 100 4-H members show pigs each summer, with many making money they put away for college.

"It could happen that yeah, there would be no county fair pigs and also it would be the state fair would have no pigs, it's a very good possibility," said Mr Salter.

In the meantime, Mr Salter is watching his pigs closely and requiring anyone coming to his farm to wear disinfected rubber boots.

"It was anticipated that winter time the disease would slow up but it had sped up, it's even up into Canada now so it's not a warm weather disease, the total future of it is unknown."