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Name: Ashlyn
Status: student
Grade: 6-8
Location: FL
Country: USA
Date: Summer 2011

Is there a simple way to measure bacteria in cat's water dishes without doing something with Agar? To measure bacteria in a water bowl, do I need to use a microscope? I am thinking of using different materials (metal, plastic, and glass) to see which of those has the grows the most bacteria.

Hello Ashlyn,

That is a very good idea for a science project. Usually the best way to do a quantitative analysis of bacteria content is to take a measured amount of a liquid, plate it out on some type of agar and do a colony count. This will give a basic indication of bacterial load, but not differentiate the types of bacteria. The most common type of bacteria that causes a pink film to form on water bowls and showers, etc. is Serratia marcescens. It is a fairly harmless organism that reacts with standing water. It may only adhere to the walls of the container and not be 'free floating' in the water. A microscope would not likely help unless you were able to do special stains to help see the bacteria. You might also want to add stoneware or ceramic to your list. Just so you know stoneware or ceramic make the best containers for cats to drink out of. It keeps the water fresher: Maybe less bacteria? You might just have to rely on a visual inspection of the containers to see which has more pink per surface area.

I hope this helps a little.

Lou Huzella

Louis M. Huzella, DVM, Diplomate, ACVP
Veterinary Pathologist
ACVP – American College of Veterinary Pathologists (Board Certified)

Click here to return to the Veterinary Topics Archive

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