Testing at Organic Pastures did not detect the strain of E. coli that sickened some of the children, but a government report last February said the dairy was likely responsible.
The lawsuits, filed by the families of 11-year-old Laura Herzog of Rancho Cucamonga and nine-year-old Chris Martin of Murrieta, allege Martin has incurred more than $450,000, and Herzog more than $250,000 in hospital bills.
The dairy's owner Mark McAfee was traveling and not immediately available for comment.