Spirocerca lupi infection in the dog: aberrant migration.

The nematode Spirocerca lupi (S. lupi), a parasite of dogs and other carnivores, affects mainly the esophagus and the aorta leading to gastrointestinal, respiratory, and circulatory signs. Aberrant migration of the worm to unusual anatomical structures, especially the thoracic cavity, resulting in atypical clinical signs is being reported more frequently. Aberrant migration of S. lupi is reviewed, and two such cases (i.e., migration to the heart, causing an aortico-pulmonary "window-like" opening, and to a subcutaneous abscess in the caudal thoracic region) are presented.