3-Year-Old FS Mixed Breed Dog

Signalment & History

A 3 year old FS mixed breed dog presents to your clinic with a 3 month history of progressive exercise intolerance and cough.

On physical examination, increased lung sounds are ausculted.

VD thorax Right lateral thorax Left lateral thorax


On the VD projection, the heart appears wider, particularly in the region of the right ventricle. However, there is no evidence of right ventricular enlargement on the lateral projections. The main pulmonary artery is enlarged. The pulmonary arteries are enlarged, tortuous, and in some areas, appear blunted.


Tortuous, enlarged, and blunted pulmonary arteries and MPA reflect damage to the intima of the vessels and the presence of thromboemboli. The suspected enlargement of the right ventricle is related to pulmonary hypertension caused by the pulmonary arterial changes, also termed cor pulmonale.

In 1987, Dr. Ackerman wrote a review article entitled “Radiographic Aspects of Heartworm Disease*” documenting the imaging findings associated with this disease. With today’s preventatives, we see far fewer cases of this disease today, but it is important for every veterinarian to be familiar with its radiographic appearance.


*Seminars in Veterinary Medicine and Surgery (Sm Anim). 1987 Feb;2(1):15-27