Immunological and hematological response in experimental Toxocara canis-infected pigs

The relationship between the immunological and hematological response to in fection was studied in pigs inoculated experimentally with Toxocara canis. Two groups of four pigs were infected with doses of 1000 and 2000 infective eggs, respectively. Two uninfected animals were used as negative controls. Blood samples were collected from each pig once a week. Serological examin ation by ELISA to determine antibody levels against T. canis L-2/L-3 excret ory-secretary (ES) antigens showed values higher than the positive cut-off point (1:32) for both the infected groups. These values increased from day 7 p.i, and remained high during the experimental period until day 56. Signi ficant differences were recorded for the two inoculating doses (p less than or equal to0.01) from day 14 to 42 p.i. Western blots run on day 7 p.i. wi th serum from the 2000 eggs group showed two polypeptide bands of 70 and 55 kDa. These same bands were observed for both infected groups from day 15 p .i. until the end of the experiment. Eosinophil counts were significantly h igher (p less than or equal to0.05) for both inoculated groups between week s 2 and 7 p.i, as compared with the control group. No significant changes w ere observed for other blood parameters. The pig is a useful animal model s ince T. canis induces an early immunological response and ELISA can detect the presence of these antibodies against;T: canis L-2/L-3 ES antigens in an imals inoculated with low doses of Toxocara eggs. (C) 2001 Elsevier Science B.V. All rights reserved.