There have been 114 cases of Porcine Epidemic Diarrhea Virus (PEDV) in Ontario in the last five years after two more farms were confirmed to have the disease in May.
The disease was confirmed at a Lambton County finisher farm on May 1 and a Middlesex County wean-to-finish farm on May 15.
There have been nine cases in Ontario this year. There were only six in all of 2017.
The disease causes watery diarrhea, vomiting and dehydration and can kill 50 to 100 per cent of young pigs.
New research from Iowa and Minnesota says flies can potentially spread PEDV after flies tested on pig farms that had PEDV were carriers of the virus.
