When in heat, many dogs become restless. The hormones may cause them to become more anxious, and they become focused on searching for a mate. Your dog may also be annoyed by the discharge. You can try using a product called DAP, dog appeasing pheromone which many dogs find calming, or you can try distracting her with play. If your dog seems lethargic, doesn't eat or drink or eliminate regularly, then there may be something medical at play that may require a visit to the vet.