Multidrug-Resistant Bacteria in Small-Animal Veterinary Healthcare Settings: Mapping the Evidence on Bacterial Contamination, Antimicrobial Resistance, and Detection Sites

Environmental contamination in veterinary healthcare facilities may contribute to the persistence and potential dissemination of multidrug-resistant (MDR) bacteria, thereby creating challenges for infection control and clinical management. This evidence map synthesized findings from 96 studies published between 2010 and 2025 investigating bacterial contamination and antimicrobial resistance in small-animal veterinary healthcare facilities and among veterinary personnel. Swabbing was the predominant sampling method, used exclusively in 56 studies (58.3%). Resistance-targeted selective and/or chromogenic culture media were used in 41 studies (42.7%). Among the clinical areas, intensive care units showed the highest proportion of studies reporting MDR bacteria (13/20, 65.0%). Regarding individual sampling sites, MDR bacteria were reported in sampling cages (61.4%) in 27 of 44 studies. High proportions of studies also reported MDR detection for scales (8/11, 72.7%), ultrasound equipment (10/15, 66.7%), sinks (13/21, 61.9%), and computer keyboards (19/32, 59.4%). Staphylococcus was the predominant reported genus (58 studies, 60.4%), while MDR S. pseudintermedius and S. aureus were reported in 27 (28.1%) and 25 (26.0%) studies, respectively. These percentages represent the proportion of studies reporting MDR detection and should not be interpreted as estimates of prevalence. Among resistance determinants, mecA was the most frequently reported gene. These findings highlight the widespread detection of multidrug-resistant bacteria across veterinary clinical environments and support the need for systematic environmental surveillance and strengthened infection prevention measures.