There is no definitive answer to this question as it depends on the individual dog's individual health and temperament. However, some dogs may be more sensitive to medications than others, so it is important to speak with your veterinarian before giving your dog a Xanax tablet. Additionally, it is important to be aware that Xanax can also cause feelings of dizziness, lightheadedness, and even fainting. If these effects become too much for your dog to handle, it may be necessary to seek medical help.