Companion animals as sentinels for community exposure to industrial chemicals: The Fairburn, GA, propyl mercaptan case study

Objectives. This study utilized the electronic medical records of six veterinary hospitals (operated by Banfield, The Pet Hospital®) in the vicinity of Fairburn, Georgia, to assess the health of dogs and cats following the unintentional release of propyl mercaptan from a waste-processing facility. Methods. Standardized electronic medical records were used to define clinical syndromes (eye inflammation, gastrointestinal, respiratory, fever, general weakness/change in mental state) in dogs and cats. The frequency and geographic distribution of each syndrome was evaluated before, during, and after the chemical release, using control charts, density maps, change in average mean distance from a suspected point source of chemical release, space-time statistics, and autoregressive integrated moving averages. Results. No consistent pattern of change in syndromic events was observed following the suspected release of propyl mercaptan. Some syndromes, including respiratory syndrome in cats, gastrointestinal syndrome in dogs, and eye inflammation syndrome in both cats and dogs, showed a change in time and spatial patterns following the release of propyl mercaptan into the community. These changes were consistent with clinical signs observed in people during a previous propyl mercaptan release in California as well as the release in Fairburn. Conclusions. A systematic review of electronic medical records of dogs and cats exposed to release of propyl mercaptan showed no conclusive and consistent evidence of adverse health effects. Methods for the use of medical records of pets for detecting environmental hazards require further development and evaluation.