Pet feeding habits and the microbiological contamination of dog food bowls: effect of feed type, cleaning method and bowl material

Background: Safe pet feeding practices and food bowl hygiene measures are important for minimising the risk of microbiological contaminations in the domestic environment. This study compares the practices reported by dog and cat caregivers, and investigates whether cleaning method, feed type or bowl material affects the microbiological contamination of dog food bowls. Results: Data from 351 dog caregivers and 186 cat caregivers were collected via an online survey. The majority of dogs (70.7%) were fed twice daily, whereas cats (43%) were mostly fed ad libitum. The most common material for dog food bowls was metal (67.1%) versus plastic (38.1%) and metal (37.6%) for cats. Dog food bowls were most frequently cleaned after each meal (35.7%); whereas for cats, 21.5% were cleaned after each meal, 22.7% once a day and 19.3% 2-3 times a week. Total mesophilic aerobic bacteria counts (TMABc), Enterobacteriaceae counts and pathogenic bacteria (Salmonella spp., Campylobacter spp., Verotoxigenic E. coli [VTEC]) were assessed for 96 dog food bowls. TMABc were higher in metal vs. plastic bowls (p < 0.001) and in those used for wet food vs. dry food (p = 0.0397). Enterobacteriaceae counts were higher in bowls washed by hand vs. dishwasher (p = 0.0515), whereas no differences were found between hand washing vs. dry wiping. Salmonella spp., Campylobacter spp. or E. coli VTEC contaminations were not detected. Conclusions: The surveyed Italian dog and cat caregivers reported different habits concerning feeding frequency, food bowl material and cleaning frequency. Wet food and metal bowls were associated with higher levels of microbiological contamination of dog food bowls. Furthermore, in relation to wet washing methods, contaminations were likely to be greater following hand washing than they were following the use of a dishwasher. Practical guidelines for safe feeding practices and hygiene measures are needed to minimise the risk of microbiological contaminations in domestic environments.