Congestive Heart Failure
Old, overweight pugs may be prone to congestive heart failure. This condition occurs when the heart is too weak to pump blood adequately, causing fluid to accumulate in the lungs. Suspect congestive heart failure if your pug coughs frequently, has trouble breathing, seems restless at night, or tires easily with only mild exercise. Congestive heart failure can't be cured, but diet, medication, and rest can ease the signs for a time. Also, weight loss can help.