However, Cocker Spaniels need to know who is alpha dog or they may start displaying a more dominant side of their character. They are quite sensitive to loud noises which can stress them out as can any heavy handling which could result in a nervous and timid dog. Cockers benefit from positive reinforcement training and need to be handled firmly yet very gently when they are being put through their paces. They also need to be given lots of mental stimulation to be truly happy and healthy dogs.