Experimental Paragonimus kellicotti infection in dogs

The life cycle of Paragonimus kellicotti was studied in dogs fed 25 or 50 metacercariae obtained from the hearts of naturally infected crayfish. Young flukes excysted in the intestines and appeared in the peritoneal cavity within 7–14 days after inoculation (DAI) and in the pleural cavity from 7 to 43 DAI. Immature flukes penetrated the pulmonary parenchyma between 7 and 10 DAI and became sexually mature between 28 and 35 DAI. Virtually all growth of the flukes occurred in the lungs. Eggs first appeared in feces 30 DAI. Pulmonary lesions were caused by the penetration and growth of flukes and the lesions were first detected by thoracic radiography 3 weeks after inoculation. Clinical signs were generally mild and consisted of an intermittent cough. Two dogs died suddenly of pneumothorax due to the rupture of cysts 32 and 35 DAI, respectively.