Which of the following is not an anxious behavior exhibited by dogs during restraint or handling?

Playing is not an anxious behavior exhibited by dogs during restraint or handling. When a dog is anxious, its natural instinct is to display certain physical and behavioral signs of distress. These can include pacing, which indicates restlessness, as well as panting or trembling, which are common physiological responses to anxiety. Tensing of muscles also reflects a dog's stress or discomfort level. In contrast, playing represents a relaxed and positive state of behavior, suggesting that the dog is comfortable and not experiencing anxiety. Therefore, while anxious behaviors are focused on signs of stress and discomfort, playing distinctly indicates a carefree and happy demeanor.