Over twenty years ago we had a pet Dachshund named Felix. He was not a fan of the squirrel or any other small animal. He was a good hunting dog and tracker. He could track people and other animals. I trained him to respond to a Acme dog whistle. Off leash we would hunt squirrels. Not the way you might think. He would stop and point if he saw one. I would then give him a whistle signal to chase the rodent and or stop if needed. I would time the signals so he would never catch the squirrel. Squirrel would always make it to the tree intime. After our hunting trips he would be so happy. He would have been crushed to find out I timed it so he would not ever get the rodent.