Multiple infection with Toxocara canis. Influence of antihistamines and corticosteroids on the histopathological response.

The histopathology of the tissues of mice infected with ten doses of 100 embryonated eggs of Toxocara canis and the influence of antihistamines and corticosteroids on these findings is described. The main lesions were confined to the liver and lungs. In infected but untreated control mice hepatic lesions consisted of periportal infiltrates, widespread foci of liver cell necrosis and polymorphonuclear and mononuclear accumulation and a few fibrotic granulomata. Treatment with antihistamines did not change these findings significantly, but corticosteroids decreased the amount of cellular infiltration and the size of the lesions. Pulmonary lesions consisted mostly of confluent infiltrates of polymorphonuclears, eosinophils and mononuclear cells with some macrophage proliferation. Neither drug seemed to affect the lung involvement.