Last week the Montana Pork Cooperative reported that Porcine Epidemic Diarrhea, or PED, had infected pig barns in Hutterite colonies near Harlowton and Great Falls.
Hutterite colonies make up about 95 percent of the state's $24 million hog industry.
PED does not affect other animals or people but it can be deadly to very young piglets.
NBC Montana visited a Gallatin County hog farmer Tuesday to find out how he is keeping his animals safe. Nathan Brown helps run Amalthea Dairy Farm just outside Bozeman. They raise goats, chickens, and pigs.
He told us, "It would be just a huge blow if we were to get something like this."
Brown says he's heard of PED and worries what might happen if it shows up in Gallatin County.
The virus can affect all ages and breeds of pigs, but hits piglets the hardest. Many times the disease can be fatal for such young pigs.
Brown explained, "They get really dehydrated, have the scours and are throwing up."
The disease can rapidly dehydrate the newborns, killing them soon after they contract the virus. PED is fatal in nearly 100 percent of cases among still nursing piglets.
"It'd be pretty tough for small park producers like myself to lose 40 to 50 percent of my litters," Brown said.
Brown went on to tell us such losses could force him to cut production and possibly turn away business. That would have far reaching consequences for entire communities.
"Higher prices to the consumer and for the swine producer," Brown said. "It could put a lot of us out of business."
Brown is taking steps to protect his animals, including limiting who has contact with his pigs. He says he's, "Making sure they haven't been in contact with other swine operations."
The potential for damage causes Brown to be afraid of what he calls a scary disease, for his farm and his normally resilient pigs.
"If it's killing them off like that it's pretty terrible," said Brown.
PED has been around in Europe and Asia for some time, but is relatively new to the United States. We spoke to Montana State Veterinarian Marty Zaluski to learn about the history of PED.
It was first discovered in the U.S. in April 2013 showing up in Iowa, Indiana and Ohio. It soon spread across the Midwest to more than 10 other states before reaching Montana.
Once a herd of swine is infected, it can spread rapidly between pigs.
No one is quite sure how the virus made its way to the United States but Zaluski says it's here to stay.
Zaluski explained how farmers can minimize risk, "Biosecurity is really what we've been trying to stress to hog producers. And really by that I mean we are asking swine owners to expect or treat all outside traffic as being potentially contaminated."
In January, national farm corporation Smithfield told the Wall Street Journal PED could lead to anywhere between 2 and 3 million pig deaths this year.
Scientists are working on a vaccine.