When disproportionately sized things are paired with each other, it's a spectacle—a spectacle that runs the gamut from alarming to hilarious.
Why else would a movie studio release Twins—a comedy based on the fact that human slab Arnold Schwarzenegger towers over the diminutive Danny DeVito—or why squeezing Will Ferrell into a tiny pair of gym shorts never gets old?
The same logic applies to people and their dogs. (Though, seeing a small child trying to walk a Great Dane is an example of a situation that could be alarming and hilarious.)
Athletes tend be larger than everyone else. And like the rest of us, athletes love their puppies as furry, infuriating children that skate by on their adorableness.
So, there are some great pics on the "Interwebs" that capture the wonderfully goofy dynamic of big athletes with wee dogs.