The purpose of this project is to determine whether or notthere are qualitative and quantitative differences in fecal Salmonella colonizationbetween symptomatic and asymptomatic dogs in the Pacific Northwest region ofthe USA. Salmonellosis is one of the most important food-borne diseases andcauses substantial medical and economic burden worldwide. Although food isthe main source of Salmonella infection in humans, non-food Salmonella sourcescan include pets (particularly dogs and cats), as well as their foods, snacks, andsupplements. The most common symptoms of salmonellosis in humans oranimals is gastrointestinal disease and Salmonella bacteria are shed via infectedfeces. Dogs in particular often do not show signs of salmonellosis when infected.Recent studies show that 14% to 25% of asymptomatic household dogs canshed Salmonella into their environment. Also a recent outbreak of humansalmonellosis, primarily in toddlers, was linked to commercial dry dog food.There remains a significant gap in knowledge regarding factors associated withdifferences in Salmonella carriage between dogs with or without gastrointestinaldisease. This proposal will test the hypothesis that dogs with Salmonella-associated gastrointestinal disease have both a higher prevalence of fecalSalmonella colonization than asymptomatic dogs, and higher fecal counts ofSalmonella bacteria than asymptomatic dogs with fecal Salmonella. Feces andpet-related management data from a minimum of 150 symptomatic and 150asymptomatic dogs will be collected from dogs presented to the veterinaryteaching hospital at Washington State University, College of Veterinary Medicineand private veterinarians from Alaska, Idaho, Montana, Oregon, and Washington.Feces will be cultured for Salmonella using standardized methods from ISOstandard 6579:2002 identified to specific serotype, and quantified usingconventional most-probable-number (MPN) culture techniques. Results of thestudy should provide new information regarding prevalence and risk factors forSalmonella colonization in asymptomatic and symptomatic dogs brought toveterinary clinics, and the relationship of bacterial load to gastrointestinaldisease.
Determining the amount, type, and risk factors of fecal Salmonella carriage in dogs, and its relationship to clinical disease, will fill a knowledge gap in understanding of salmonellosis in pet dogs. In particular, quantitative data for Salmonella infection in dogs could assist in developing quantitative microbial risk assessment methods to aid in managing the risk of salmonellosis in humans cohabiting with pet dogs.
