Dogs breathe through their respiratory system, a series of airways that comprise the nasal passages, throat, windpipe, and bronchial tubes that lead to the lungs. Any of the following symptoms indicate a problem in the system: rapid breathing, noisy breathing, and coughing.

Rapid Breathing

Dogs will breath heavily and rapidly in a number of circumstances, such as after strenuous exercise, in excessive heat, or if they're excited or stressed. If your dog is breathing rapidly while at rest and you can't attribute her condition to any of these other factors, consult your veterinarian.

Noisy Breathing

This includes wheezing, sneezing, labored breathing, hoarseness, and any odd sound the dog makes while trying to breathe. Owners of some shortfaced breeds live with this problem. Their dogs have shorter airways and will regularly snort, snore, or breathe heavily. For other dogs, noisy breathing is generally due to an obstruction, though it can also indicate a lung disease or heart failure. It's best to have your veterinarian listen and look.

Coughing

Coughing results from the effort to extricate an obstruction in the airways, whether it's a bone chip, a collapsed windpipe, or fluid buildup in the lungs caused by a respiratory disease such as kennel cough. Kennel cough is highly contagious between dogs and can spread rapidly at a dog show or in a kennel. There is a vaccine to help prevent kennel cough, and if it's caught early, treatment is successful.