Changes

===Radiography===

===Radiography===

In dogs, thoracic radiography provides good information on disease severity and is useful for screening dogs showing clinical signs compatible with ''D. immitis'' infection¹. However, thoracic radiograph do not neccessarily reflect the current worm burden: radiographic signs of advanced disease can persist long after an infection has run its course⁴. Conversely, dogs with high burdens may be inactive and thus show few clinical signs or radiographic changes. Radiographic signs are mild-to-moderate in class II disease, but become more obvious in class III infections. The main pulmonary artery is enlarged,sup>1, 4</sup>, and the caudal lobar vessels appear tortuous¹ Ill-defined, fluffy infiltrates are apparent, and often surroung in the caudal lobar vessels. Right-sided cardiomegaly may be appreciated, and pleural and peritoneal effusions can be noted if right-sided congestive heart failure occurs⁴.

In dogs, thoracic radiography provides good information on disease severity and is useful for screening dogs showing clinical signs compatible with ''D. immitis'' infection¹. However, thoracic radiograph do not neccessarily reflect the current worm burden: radiographic signs of advanced disease can persist long after an infection has run its course⁴. Conversely, dogs with high burdens may be inactive and thus show few clinical signs or radiographic changes. Radiographic signs are mild-to-moderate in class II disease, but become more obvious in class III infections. The main pulmonary artery is enlarged^{1, 4}, and the caudal lobar vessels appear tortuous¹. Ill-defined, fluffy infiltrates are apparent, and often surround the caudal lobar vessels. Right-sided cardiomegaly may be appreciated, and pleural and peritoneal effusions can be noted in right-sided congestive heart failure⁴.

Cardiac changes on thoracic radiography are less common in cats than dogs. The caudal lobar veins are enlarged (greater than 1.5 times the width of the ninth ribe), and the pulmonary arteries are blunted and tortuous^{3, 5}. Patchy parenchymal infiltrates may be seen in the region of vessels in animals showing respiratory signs^{1, 3}. Enlargement of the main pulmonary artery cannot normally be seen in cats, as it is has a relatively midline position and is thus obscured by the cardiac silhouette^{1, 5}. Right-sided cardiomegaly is not considered a typical finding in the cat⁵.

Cardiac changes on thoracic radiography are less common in cats than dogs. The caudal lobar veins are enlarged (greater than 1.5 times the width of the ninth rib), and the pulmonary arteries are blunted and tortuous^{3, 5}. Patchy parenchymal infiltrates may be seen in the region of vessels in animals showing respiratory signs^{1, 3}. Enlargement of the main pulmonary artery cannot normally be seen in cats, as it is has a relatively midline position and is thus obscured by the cardiac silhouette^{1, 5}. Right-sided cardiomegaly is not considered a typical finding in the cat⁵.

===Echocardiography===

===Echocardiography===