The three were among a group of people who fell ill after eating the salami at an agritourism farm in the province of Belluno, local newspaper Il Gazzettino reported.
They were reported to have suffered vomiting, stomach aches and nausea.
Two people, including a young boy, were admitted to hospital for observation; test results are expected in the coming days.
While the cause of the toxin is yet unknown, the only person in the group to escape sickness did not eat the salami.
The cause of the sickness could be water contaminated after recent heavy rains, the newspaper said.