Dog breathing problems are a cause for concern. All dogs are susceptible, but Brachycephalic breeds are even more so. Brachycephalic breeds are the types of dogs with "snub" noses, such as the Pug, Pekingese, Boston Terrier, Boxer, Shih-Tzu, etc). These dogs should be monitored even more closely for any signs of breathing or respiratory problems, particularly in hot or humid conditions. Although some respiratory conditions may end up being harmless, it's still better to be safe than sorry - take your dog to the vet to ensure all is well.
Coughing can have other causes as well, including asthma, a collapsed trachea or by kennel cough.
Breathing or respiratory problems are not that uncommon of a dog health problem. But there are many causes of respiratory problems, some benign while others are serious. Not all can be easily diagnosed. Become familiar with your dog's normal breathing patterns, such as how many breaths he takes on average. This can help you determine whether you have an emergency health problem on hand. Get your dog to a vet immediately if he is having difficulties breathing.