While concerns have been expressed about the feeding of raw meat to pets, little attention has focused on the potential for infection from contaminated meat or objects that have been in contact with contaminated food. This study sought to assess the persistence of Salmonella species and the effects of different cleaning regimens on experimentally infected food bowls. Stainless steel and plastic pet food bowls were experimentally inoculated with Salmonella Copenhagen that had been previously isolated from a commercial raw pet food. The bowls were then cleaned in 1 of 6 ways. The total percentages of bowls (stainless steel and plastic combined) from which Salmonella species were recovered were as follows: 100% in the control group (no cleaning); 96% in the warm-water rinse group; 96% in the rinse and scrub group; 79% in the scrub with soap group; 71% in the 10% bleach soak group; 67% in the dishwasher group (run at 85o C); and 42% in the scrub plus bleach soak group. Salmonella persistence did not significantly differ between stainless steel and plastic bowls. The persistence of Salmonella, even when bowls were soaked in bleach or washed in the dishwasher, was tentatively attributed to the presence of organic debris in the bowls. The authors conclude that avoidance of feeding raw-meat diets would be prudent; in cases where such diets are fed, caution must be exercised in handling the food and any items in contact with it.

COMMENTARY: Feeding raw diets to pets is a popular alternative for some owners looking for a more natural or hypoallergenic alternative to manufactured diets. This study illustrates one aspect of the risk to this option-indirect transmission of enteropathogens from food bowls. As the authors point out, the study does not confirm the risk for transmission, especially because it did not quantify the actual amount of bacteria isolated, but it does highlight some concerns. Pet owners must recognize these potential risks when considering feeding a raw diet, particularly if the home includes humans at high risk for infection, such as infants, the elderly, and the immunocompromised.

Survival of Salmonella Copenhagen in food bowls following contamination with experimentally inoculated raw meat: Effects of time, cleaning, and disinfection. Weese JS, Rousseau J. CAN VET J 47:887-889, 2006.