Rodent contamination of soft drinks: An evaluation of postmortem changes

Eight rodents were submitted for necropsy after being found in soft drink beverages. To determine whether the postmortem changes in these mice were consistent with contamination at the time of bottling/canning or after the beverage was opened by the consumer, we conducted a study of the effects of prolonged rodent submersion in soft drinks. Thirty unmanipulated laboratory mice, euthanized for other reasons, were placed in bottled beverages (diet and regular cola, sweet and unsweetened tea, seltzer water, and water) for time intervals ranging from 3 days to 2 months. Starting at the 1-week time point, all rodents submerged in sealed carbonated beverages at room temperature showed severe, full-body gas distention. This change was not seen if the bottle was uncapped or if the beverage was refrigerated. Other significant changes included staining of the incisors starting at 1 week in the colored beverages (colas, teas), and erosion of the occlusal surface of the incisors starting at 2 weeks in the acidic beverages (colas, teas, seltzer). Visceral decomposition increased with time in all the beverages, but was most rapid in the regular cola. The mice submitted for necropsy showed no gas distention, no incisor erosion, and visceral decomposition similar to the experimental mice at the 1-week time point. As the interval between production and opening ranged from 3 weeks to 3 months, these results suggest that the rodents entered the beverage containers after they were opened by the consumer.