Have you ever heard of the Collie dog? Its a herding god.
yes i have they are very short
One of my favorites is the Border Collie, which is used to herd livestock
that my favorite too. but i also like pit bulls
I prefer collies cause they can be trained and to act on the sound of a whistle.
pits can be trained as well. they behave so well. 
I did not know that. However collies are very active and agile.
you'd think it would be hard considering how short they are