Around 50 dog owners and several dogs are believed to have been infected with enterohaemorrhagic E. coli (EHEC) following a dog show in eastern Sweden.

"We’re right in the middle of investigating where the bacteria came from," Britt Åkerlind of the infectious disease unit of Östergötland County told The Local.

So far, two Swedes have been confirmed as infected by EHEC, one from Skåne in the south, and another from Gothenburg in the west.

"But we’re expecting more confirmed cases to come in," said Åkerlind.

Those infected with the bacteria all attended a dog show near Norrköping in eastern Sweden held the first weekend in June.

Of the roughly 120 participants, who traveled from all over Sweden as well as from Denmark, Norway, and Finland, about half have come down with symptoms stemming from EHEC infection.

"We’ve also received reports that some of the dogs have had upset stomachs," said Åkerlind, who labeled the outbreak as "quite large."