We think that the dog saliva will be the dirtiest.  This is because dogs almost never brush their teeth.  Dogs also clean themselves with their tongues and humans take showers and brush teeth.

^{_{Research:  Google AI overview}}

^{_{Dogs' saliva is not cleaner than human saliva.}}

^{_{akc - the mouths are full of microbes and it's hard to compare.}}

^{_{interview with Dr. Lorraine Natho - treating dog bites as a doctor is much more serious than human bites because of the bacteria involved.}}
 

Manipulated:

Dog saliva vs human saliva

Responding:

How much bacteria grows after 6 days

Controlled: 

-Saliva test at the same time

-Same amount of saliva

-Same type of agar plate

1.we swab the dogs mouths and our mouths 

2.observe the growth over a six day period

3.write down observations

4. Repeat the cycles two more times.

We saw a lot of different kinds of bacteria. There was some white,green and orange spots on the human and the dogs.

dog bacteria grew the first day and it took longer for the human bacteria to grow.

The dog bacteria grew in different patterns and was very spread out.  Human bacteria was in spots and had small growth.

We found that dog bacteria grew faster and spread more. We will do two more rounds of testing to compare.  The dogs we tested eat kibble and do not brush teeth.  The humans eat many foods and do brush teeth.  From our data we saw that humans do have bacteria but not as much as dogs. 

We saw that the dogs saliva was the most dirty because it was larger and grew the fastest.  The dog backster has the dirtiest mouth.  We wondered if it makes a difference when the dogs ate food.  We did test the dogs at the same time (after dinner) each day.  We are testing two more cycles to see if their are any changes  

This project is important because if a human comes into a hospital with a dog bite then a vet needs to treat them differently because of the bacteria in the cut.  A bite from a human would be different because it has different bacteria.  

What did you do that might have introduced errors to your experiment?

1. How long do we brush our teeth?
2. How long we swabbed the mouths and how much saliva we collected.
3. What did everyone eat before the test?
 

"Saliva (Spit)" Cleveland Clinic, 19, 03, 2025, https://my.clevelandclinic.org/health/body/saliva

"Is a dogs mouth cleaner than a humans." American Kennel Club, 19, 03, 2025, https://www.akc.org/expert-advice/health/is-dogs-mouth-cleaner-than-humans/

Lilah’s dad helped a lot so did Lilah’s mom and Annabelle’s mom.  Mr. Z also helped us organize our information. Thanks to all of the Dog Owners who let us swab their dogs mouths.