The creator and artist of Scooby Doo was Iwao Takamoto. Takamoto did a bit of research before creating the beloved character of children and adults alike. He spoke with a breeder of Great Danes who informed him of what a show-ready pedigree Great Dane would look like.
Takamoto, of course, took this information into consideration, but he probably used the information the opposite way of how the breeder might have expected him to use it. Instead of making Scooby, a perfect show dog, he gave Scooby several characteristics opposite of the show standards.
Scooby was given completely the wrong colorization as well as a humped back, bowed legs, and small chin. Since Scooby is a cartoon, he was also given some unrealistic characteristics. For example, Scooby’s tail has far more capabilities than any real dog’s tail would have.
He can use it to hang from or even press buttons. Scooby’s face is also “malleable,” which means that it could be adjusted in unnatural way to communicate emotion. He also has only one pad on the sole of his feet, which is inaccurate, but make Scooby easier to draw.