Dogs pant all the time, it is the way they cool down. They pant when it is hot and after exercise. Panting is also a sign of increased respiration, which happens when dogs get excited. Panting in these circumstances is completely normal. Panting that is not related to these circumstances could be a signal for concern.
Dogs breathe primarily through their noses. Sometimes, when the temperature is hot or if the dog has been exercising, it needs to take in more air, so the dog engages in mouth breathing or panting. Panting allows more air to circulate, oxygenating the blood. Panting also allows for heat loss by evaporation, cooling the dog down.
Panting may be a cause for concern if it is excessive and seemingly unrelated to the circumstances. If, for example, the temperature is not hot and the dog is not exercising, sudden excessive panting merits further investigation. If the dog is excited, anxious or nervous, this state of mind can explain the excessive panting. Similarly, if it is a pregnant dog close to term, sudden excessive panting indicates the dog is in labour.
Medical Reasons for Excessive Panting
Some illnesses and medications cause dogs to pant excessively. Dogs that are about to vomit also often pant excessively. Sometimes dogs vomit because they ate or drank too much too quickly. Other times they pant and vomit for a medical reason. A sudden onset of excessive panting unrelated to temperature, exercise or mood that does not subside within 10 minutes, could be indicative of heatstroke or poisoning. If there is any reason to suspect a medical reason for the panting, the dog's mouth and tongue should be inspected to see if they are turning bluish; If so, the dog should be taken immediately to the veterinarian.
Brachycephalic dogs, such as Boston terriers, bulldogs and pugs, have compressed upper jaws, or short snouts. These dogs pant more because their soft palates are pushed farther back in their heads, constricting the pharynx and making breathing more difficult.