Dirofilaria immitis infection

Dirofilaria immitis infection in a 9-year-old Chow-chow. Adult forms of this parasite preferentially lodge in the right ventricle and pulmonary artery, shedding larval forms (microfilarias) into the blood stream, from which they can be removed by blood-drinking insects. When in sufficient numbers, the adults may disrupt blood circulation. The larvae may embolize in various organs, causing multiple lesions and contributing to the symptoms occasionally shown by infected animals.