Public health officials in Oregon suspect that the 4-year-old girl who died from an E. coli infection in September was infected by droppings from the family’s pet goat, according to a report by Lynne Terry at The Oregonian. However, lab tests have not been conclusive, and the state health department is still working to try and determine the exact source of Serena Profitt’s infection. Her parents say they’re feeling frustrated about the lack of certainty.

A family friend, 5-year-old Bradley Sutton from Tacoma, WA, also fell ill with E. coli O157:H7 and spent nearly a month on dialysis in the hospital. He’s now on seven medications, requires blood work every three days, and only has 10-percent kidney function, according to the report. The two children shared food and even fed the goat part of a watermelon that they both ate. Lab tests on the goat’s droppings revealed E. coli contamination, but officials have not yet connected that E. coli to the strain that sickened the children. Serena Profitt died Sept. 9 at Doernbecher Children’s Hospital in Portland.

Health officials advised the family to euthanize the goat, which they won’t do. It’s currently staying with some neighbors. E. coli infections can come from a variety of sources, including food, water and animals. A number of high-profile illness outbreaks in recent years have been linked to animals at petting zoos.