It wasn't an old squirrel, or a sick squirrel.
It was a too-slow, stupid squirrel.
I was just bringing the dogs back to the house, Golly in the lead. When down the path comes strolling this gray squirrel. It goes nose-to-nose with Golly. They're both startled (you can imagine!) and the squirrel finally figures out "uh-oh," turns around and high-tails it (literally) for the gate at the front of the house.
Dax was in the back yard at the time. She beat the squirrel to the gate.
Fast puppy. Slow squirrel.