The heart of a working dog The heart of a strong working dog is the foundation upon which all the rest of its temperament depends. It is the essence of the animal, the ground of its being as far as work is concerned. The psychological balance from which physical prowess can be directed in dog work is totally dependent upon nerve and resilience. There's nothing more necessary to a real working dog than its nervous system and its resilience. The dog who can, without upsetment, without fear, without signs of nervous tension, flight reaction, worry, whining, etc., accept its entire universe all of its environment with every characteristic of heat, cold, noise, population, surprise, etc. is a dog of strong nerve.
Nerve is a sine qua non for the working dog.
The canine nervous system provides the deep inner core of calmness and confidence upon which all the working dog's strength depends. The nervous system of a young pup may be evaluated early in life, long before it is required to face a changing environment which might be frightening and is often full of surprises. However, the final judgment on a dog's character cannot be made before all of its components have matured into a solid functioning system. The solidity of a strong nervous system is the puppy's first defense against the challenges life will place in its path. Nerve is the ability to roll with the punches.