| Abstract: | Collateral pulmonary circulation was evaluated angiographically 11 months after experimental infection of dogs with either 25 or 100 infective larvae of Dirofilaria immitis. In both groups, collateral pulmonary circulation developed from bronchial arteries and esophageal branches of the left gastric artery. Of the four dogs receiving 25 larvae, one had no detectable collateral circulation, one developed collateral pulmonary circulation from the bronchial arteries only, and two had collateral pulmonary circulation from the bronchial arteries and esophageal branches of the left gastric artery. Of the three dogs receiving 100 larvae, all had collateral pulmonary circulation from the bronchial arteries and the esophageal branches of the left gastric artery. Bronchial artery collateral pulmonary circulation was more extensive in the 100-larvae dogs than in the 25-larvae dogs. Collateral pulmonary circulation from the left gastric artery esophageal branches was similar in both dog groups. Angiographically detectable collateral pulmonary circulation developed within the first year of heaertworm infection. In some respects, the extent of collateral pulmonary circulation development was related to the severity of heartworm infection. |
