This dog typifies the “PND Hack n Gack” which is akin to COPD, which is kind of like airway Atopy, all of which are oversimplifications of airway inflammation.
Document on PND Hack n Gack download or read online: (PDF Click)
There are lots of contributors to a bronchitic / inflammatory airway disorder, for example, genetics, body weight, and age.
The case depicted is complicated by extreme body weight. The excess weight compresses the heart and lungs, causing pulmonary hypertension. Also, the extra weight compresses the airway. (Trachea)
After the exam which may include Xrays and bloodwork (to help rule out pneumonia, or congestive heart failure) – – you can safely back into a tentative diagnosis of “PND Hack n Gag” and manage that (at least initially) with anti-inflammatories, and antihistamines.
Antibiotics may be needed, but RARELY so.
Sometimes a cough suppressant aids comfortable sleep while airway inflammation is reduced.