Salmonellosis Outbreak in a Rottweiler Kennel Associated with Raw Meat-Based Diets

Background: This case describes an outbreak of salmonellosis caused by Salmonella enterica subspecies enterica serotype Agona in a Rottweiler breeding kennel, associated with raw meat-based diet (RMBD) of unlicensed origin. The report presents the clinical, epidemiological, and microbiological characteristics of the outbreak, as well as the control and preventive measures undertaken. Methods: Samples of faeces, vomitus, raw food, and environmental surfaces were examined. The isolated pathogen was identified using bacteriological culture, biochemical testing, MALDI-TOF mass spectrometry, and serotyping according to the White–Kauffmann–Le Minor scheme. Antimicrobial susceptibility was determined by the broth microdilution method in accordance with standarts of Clinical and Laboratory Standards Institute (CLSI). Results: Clinical signs included vomiting, diarrhoea, lethargy, and dehydration without fever, with disease exacerbation observed in post-partum animals. Extensive carriage and faecal shedding of S. Agona were detected in affected dogs, along with widespread contamination of food and the kennel environment. The isolate was susceptible to most antimicrobial agents but resistant to cephalexin, aminoglycosides, lincosamides, macrolides, and fusidic acid, and showed intermediate susceptibility to polymyxin B. Following discontinuation of raw meat feeding, targeted antimicrobial therapy, and environmental disinfection, all dogs recovered, and subsequent tests for Salmonella spp., were negative. All human contacts also tested negative. Conclusion: This represents the first documented outbreak of S. Agona infection in dogs in Bulgaria linked to a RMBD. The findings emphasize the importance of feed safety, biosecurity, and traceability of feed sources in kennels, as well as the potential zoonotic risk associated with raw feeding practices. The diagnostic and therapeutic measures implemented in this case provide an effective model for managing similar epidemiological events within the One Health framework.