We have been guilty of encouraging Cort to chase the squirrels off our yard. Successfully evicting one big grey squirrel from our attic, we don't want to go through that again. We just tell Cort, "get the squirrel", when we see one and he does a fine job of sending them on their way. He runs them up the trees, then leaps, twists and follows them from tree to tree as they scold him loudly. Lately I have seen a small grey squirrel hanging around the oak trees in front.

I witnessed this inter-action recently, laughing at the silly squirrel and dog comedy act.
Up Cort leaps as little grey squirrel (LGS) scurries just far enough down the post to be out of reach.
As good ol' Cort begins his earth bound descent, LGS scampers back up to his perch on the fence post....
...... retreating just out of reach once again as Cort springs back into the air. My goodness Cort, what big, white teeth you have!
This little game went on and on for several minutes, up and down, down and up, back and forth.
I was starting to wonder when LGS was going to get tired of the barking, jumping, obnoxious dog and head off down the street.
LGS stopped the dog in a most unexpected manner.
He leaped off the fence post.... right into my dog's large open mouth.
Shocking me but pleasing the dog, I am sure. I dropped my camera, so have no photo to document the squirrel's suicide leap. I hollered, "DROP IT CORT!" -and he did!- I swear the dog gave me a look that loudly asked, "are you nuts? "
LGS panting, whimpering and limping, slowly climbed up the tree. Out of view and out of reach.
No more 'sicking' dog on squirrels........