“Why Is My Bowl Pink?” and Other Important Questions

“Why Is My Bowl Pink?” and Other Important Questions

If your pet is anything like my cat, dropping random items into their water bowl is an Olympic sport (bonus points if they manage to get all of the water displaced onto the floor). Unfortunately, there is more than just bottle caps lurking in your pet’s bowls, and some of these additions can be very harmful to your health. Bacteria, introduced either through natural means or by transfer from your pet to their bowl, thrive on your pet’s water and food bowls.

Read on to hear more about the bacteria and other microbes found in our pets’ bowls and how they can affect you:

It’s All About the Biofilm:

If you have ever felt inside your pet bowl and it felt slick and a little bit slimy, this is the first sign that your pet bowl is being colonized by bacteria. Bacteria come together to produce something called biofilm. Biofilm a slimy substance that bacteria make when they meet in places that are good spots for multiplying (in this case, your food and water bowls)4.

Biofilm helps the bacteria form a group and stick to the surface of their environment, which allows them to multiply faster and make it harder to get rid of them3.  Their growing numbers in your pet’s food or water bowl also place you at a higher risk for infection, either through contact with your pet or their bowls. Biofilm comes in a wide variety of colors; yellow, pink, orange, brown, clear, or even green, and it is exactly what’s causing your bowl to   change colors.

What Is in Your Pet’s Bowl:

While your pet’s bowl may look innocent, it is actually the perfect breeding ground for many kinds of bacteria. Pet food, either in dry kibble form, raw, or the wet kind, is full of carbohydrates, proteins and sugars that make bacteria multiply quickly. Water bowls are often used by our pets just after mealtimes and also offer the number one ingredient needed for a growing bacterium; water.

While water bowls often carry bits of food dropped from your pet’s mouth when drinking, they are also the deposit sites of all the household bacteria your pet comes into contact with through mouth, paw, or fur.  Many pet owners are familiar with their pet bowls taking on a pinkish tinge after a while. The bacteria responsible for this, Serratia marcescens, can usually be found in sinks and tubs (as well as pet bowls) because it just loves wet places1.

While S. marcescensis known for causing skin infections, endocarditis, meningitis and a host of other infections, it also typically found with a host of other bacteria. Salmonella, Campylobacter jejuni, Escherichia coli, and Staphylococcus aureusare also common visitors to your pet bowl, as they are all common kitchen bacteria that happen to thrive on the ingredients in pet bowls5. Some illnesses caused by these bacteria are: blood infections, meningitis, vomiting, diarrhea, pneumonia, infections in the heart, and other health issues. Fortunately, all these bacteria generally only affect people and pets who are already immunocompromised. Those of us who are healthy are probably not going to be sick from these bacteria, but children and older people (or those who are already ill) are very much at risk. If you come into contact with the sick, young children, or the elderly, considering taking extra precautions to make sure you don’t bring your bacteria with you by keeping an extra clean house and washing your hands often.

How Can You Prevent the Slime:

Fortunately, slimy pet bowls can be avoided in two simple steps. First, you need to purchase pet bowls that make it hard for the bacteria to stick to. Getting a metal, glass, or ceramic pet bowl makes step two much easier. The second step to preventing a buildup of bacteria in your pet bowl (and making infection from the nasties in the bowl much less likely) is to clean and refill your pet bowls frequently.

Buy a pet bowl with a surface that is easy to clean and does not pick up scratches from a good scrubbing like a plastic bowl would. Following this step stops bacteria from finding places to hide when you do scrub out their new home. Frequent washing of both your food and water bowls makes sure that any bacteria that are introduced are not allowed to multiply enough to form biofilm.

In order to keep bacteria at bay, a thorough scrubbing is recommended at leastonce a week, preferably more. Water bowls should be emptied, rinsed, and refilled with clean water every day. Consider sanitizing your bowls during their cleaning in the dishwasher or under boiling hot water to do an extra thorough cleansing.

Do you have any tips you recommend to keeping your pet bowls clean, or tricks to help you remember to clean them out every day? We’d love to hear about them in the comments!

By Lauren Pescarus


1 Opportunistic Infections Caused by Serratia marcescens. (n.d.). Retrieved May 31, 2018, from https://microbewiki.kenyon.edu/index.php/Opportunistic_Infections_Caused_by_Serratia_marcescens

3 Parsek, M. R., & Singh, P. K. (2003). Bacterial Biofilms: An Emerging Link to Disease Pathogenesis. Annual Review of Microbiology,57(1), 677-701. doi:10.1146/annurev.micro.57.030502.090720

5 Richards-Gustafson, F. (2017, November 21). What Types of Bacteria Are Found in Wet Sinks? Retrieved May 31, 2018, from http://education.seattlepi.com/types-bacteria-found-wet-sinks-4325.html

4 Soucie, W. J., & Schuler, B. (2006). Avoiding Pink Stain Pain. Opflow. Retrieved May 31, 2018, from https://www.mawc.org/sites/default/files/pink_stains.pdf.