Panting
Because dogs sweat through the pads on their feet, most of their body heat is expelled through their mouth when they pant. It's their primary means of regulating body temperature. Dogs also pant to cope with pain.
Dog barking
In nature, dogs bark to raise an alarm at the first signs of possible danger or to herald a new arrival. Barking is an important means of canine communication. See What your dog's bark is telling you.
Dog chewing
Just as a growing child, your dog will want to chew on toys and other objects to relieve the pain of a new set of teeth coming in. If your dog is full grown, you may also come home to find your couch cushions or favorite pair of shoes ripped to shreds, but it is not because they enjoy the taste. Your dog could be exhibiting signs of separation anxiety or anxiety in general.