A 10-year-old Miniature Poodle presents with a chronic cough.
On thoracic radiographs, you observe generalized cardiomegaly, elevation of the trachea, a prominent bulge at the caudodorsal aspect of the cardiac silhouette on the lateral view, and a perihilar interstitial to alveolar lung pattern.
Which of the following is the most likely radiographic diagnosis?
