On March 6, 2018 the CDC, several states and the US Department of Agriculture announced an outbreak of Salmonella Enteritidis infections linked to exposure to pet guinea pigs. The CDC began investigating the outbreak in December 2017 when CDC Pulsnet identified a cluster of three Salmonella Enteritidis infections that whole genome sequencing showed were closely related genetically. A review of the PulseNet database identified 6 more closely related illnesses dating back to 2015. In total 9 outbreak cases were reported from eight states. Illnesses started on July 17, 2015 to December 15, 2017. One person was hospitalized and there were no deaths. Epidemiologic and laboratory evidence indicated that contact with a guinea pig or its habitat in the week before illness was the likely source of the outbreak.