What’s in your pet’s bowl? The science behind safer, cleaner mealtimes.
Most pet parents have the essentials covered for their pet: access to fresh water, a complete and balanced diet, and a comfortable home (and probably more toys than they could ever play with!). But there’s one simple daily habit that often gets overlooked, and it can quietly make a big difference in a pet’s overall health: routine cleaning of food and water bowls.
It might seem minor, especially since many pets chew on or eat things far stranger than what is in their bowls. However, multiple studies have shown that pet food and water dishes carry some of the highest bacterial counts of any household item used daily.
If you’re reading this and realizing you can’t remember the last time you washed your pet’s bowl, you’re not alone. A 2022 survey found that fewer than 25% of pet parents wash their pet’s food bowl and scoop after each use.
Despite how common and important this issue is, safe food and bowl handling isn’t something most pet parents are ever taught. The FDA does offer some guidance on “Tips for Safe Handling of Pet Food and Treats,” but the information is far less detailed than the guidelines available for human food safety, and less than 5% of respondents in a survey about dog owner’s feeding practices and bowl hygiene even knew that the FDA guidelines existed.
Several factors influence bacterial levels in pet bowls, and understanding them can help us all make better choices for our pets and families. The three biggest contributors are bowl material, food type, and cleaning method.
Bowl Material: Stainless Steel vs. Ceramic vs. Plastic
Research on best bowl materials is honestly mixed. Some studies report higher bacterial levels on metal bowls, others find plastic bowls carry the most bacteria and ceramic developed the largest diversity of bacterial types, and at least one shows no significant difference at all. The large number of variables contributes significantly to the inconsistent results – including age of the bowl, smoothness of the surface, presence of scratches, chips, or cracks, and even the specific grade of stainless steel or type of ceramic glaze. The most common materials for pet bowls are stainless steel, ceramic, and plastic.
• Stainless steel: Overall performs well, but lower‑quality steel or older bowls with scratches can trap bacteria.
• Ceramic: Generally safe when new, but chips and micro‑cracks quickly become ideal hiding spots for bacteria and biofilms. If selecting a ceramic bowl, be sure to check that the glaze is lead free, and the bowl is intended for use with food.
• Plastic: Lightweight and inexpensive, but the easiest to scratch, chew, and degrade — which makes it the most likely to harbor bacteria over time.
With all of that being said, the condition of the bowl and how it is handled (we’re looking at those dogs who just can’t wait for their meal, so they chew on their bowl instead!) matters just as much as the material. Any bowl with scratches, chips, or worn surfaces will hold onto bacteria more easily.
Food Type: Dry vs. Wet vs. Fresh vs. Raw
Wet foods (canned, moist, or fresh) tend to support higher bacterial growth than dry kibble. But regardless of food type, bacteria levels increase dramatically when food sits in the bowl for 6–12 hours — especially once the food has been exposed to a pet’s saliva. Raw meat diets (even if just a component of the diet is raw) carry a significantly higher risk of bacterial growth including up to a 17x increase in pathogenic bacteria such as Clostridium difficile (C. diff) and Salmonella that persisted on pet dishes even after routine washing.
Cleaning Method: Hand Wash vs. Dishwasher vs. Dry Wipe
Common cleaning methods include hand washing, use of a dishwasher, and simply wiping the bowl without water. Surprisingly, one study found no difference in bacterial contamination between hand washing and dry wiping. This is likely due to inconsistent water temperature or contaminated/dirty sponges. Hot water (above 160°F) is far more effective than cool or lukewarm water. Overall, dishwashers tend to be the most reliable method for reducing bacterial load.
While there is not one strong piece of published data that wraps all of this information up to make a single recommendation for what bowl to use, how to properly clean it, and how to minimize risks of bacteria in homes, we should still be working on making improvements in our methods every day. Some general tips include:
Do your best to wash your pet’s bowl(s) after every meal/every time you fill the water bowl. This includes the scoop that you use for the food too!
When possible, have multiple bowls available so that you can use your dishwasher to keep them clean (and so you don’t then have to run your dishwasher every day!).
If you are handwashing the bowls, use hot water, keep a separate sponge that is used only for pet bowls, and sanitize it and/or replace it frequently to minimize bacteria load in the sponge itself.
Using new and well maintained metal bowls should help minimize bacteria loads relative to other types of bowls.
Avoid leaving your pet’s food in the bowl for any extended period of time, especially if it is a wet/canned food or has raw meat in it.
Avoid prepping your pet’s food on surfaces that are used to prepare human food.
Wash your hands before and after handling their bowls and food.
Beyond the direct impact on pets, there’s also a broader One Health perspective to consider — the interconnectedness of human, animal, and environmental health. Since pets are often fed in or near the kitchen, exposure to bacteria such as E. coli, salmonella, and methicillin-resistant Staphylococcus aureus. in biofilms pose a high risk to people. All of these bacteria can lead to human illness including GI upset, skin infections, etc. Even well‑intentioned pet parents who hand wash dishes may unknowingly spread bacteria to themselves or around their home by not washing their hands before and after handling their pet’s food and bowls, as well as by using dirty sponges, or using that same sponge for their own dishes, cooking surfaces, etc.
Taking small daily steps to improve safe pet bowl handling and maintenance can make a big difference for the health of you and your pets. You don’t need to do a full kitchen overhaul overnight but being mindful and intentional about your pet’s bowls will set you and your furry friends up for a healthier future!
Sources:
• Luisana et al. Survey evaluation of dog owners' feeding practices and dog bowls' hygiene assessment in domestic settings. PLOS ONE.
• Raspa et al. Pet feeding habits and the microbiological contamination of dog food bowls: effect of feed type, cleaning method and bowl material. BMC Veterinary Research.
• Thomas & Feng. Risk of foodborne illness from pet food: assessing pet owners' knowledge, behavior, and risk perception. Journal of Food Protection.
• Today’s Veterinary Business. Pet food bowl safety: Why cleaning frequency matters. https://todaysveterinarybusiness.com/pet-food-bowl-safety
• U.S. Food & Drug Administration. Tips for Safe Handling of Pet Food and Treats.https://www.fda.gov/animal-veterinary/animal-health-literacy/tips-safe-handling-pet-food-and-treats