sounds that puppies make as pacifying and soliciting sounds. Soft whining and whimpering – hurting or scared. Moan or moan-yodel, lower pitched than whines or whimpers – spontaneous pleasure or excitement. Single yelp or high-pitched bark – response to sudden, unexpected pain such as a too-hard play bite. Series of yelps – severe fear or pain. Screaming A yelp for several seconds in length much like a human child, then repeated – anguish or agony, a call to the pack-mates for help, is rarely heard. It should also never be ignored, as it could be an indication of severe injury. If your dog screams, take it to the vet immediately Panting Panting is an attempt to regulate body temperature. Excitement can raise the body temperature in both humans and dogs. Although not an intentional communication, if the dog pants rapidly even though it is not exposed to warm conditions or intense physical activity, then this signals excitement due to stress. Sighs Sighs are an expression of emotion, usually when the dog is lying down with its head on its paws. When the eyes are half-closed, it signals pleasure and contentment. When the eyes are fully open, it signals displeasure or disappointment. Play Sneezing Play sneezing is another calming signal that dogs use to indicate that they are not being aggressive, or that they are just playing. Play sneezes are not actual sneezes, but more of an expulsion of air that resembles a sneeze, and occur frequently during play. Olfactory Dogs have an olfactory sense 40 times more sensitive than a human's and they commence their lives operating almost exclusively on smell and touch. The special scents that dogs use for communication are called pheromones. Pheromones are composed of natural chemicals that mediate olfactory communication with conspecifics. These pheromones that contain chemical signals serve to send information to other dogs about social status, age, sexual or reproductive status, aggressive behavior, and territorial marking. They can serve to either attract or repel other dogs. Pheromone signals are received in the vomeronasal organ (VNO) that is included in the olfactory tract. In order for a dog to detect a stimulus, or odor, the VNO has to be opened. It is opened when a pheromone attaches to the membrane of the nervous cells in the vomeronasal organ. From the VNO, the pheromone signals are sent to the accessory olfactory bulb and transferred to the