Dynamic of Ascaris suum on a swine farm in the Carlos Arvelo municipality in Carabobo state-Venezuela

A study of the dynamic of Ascaris suum infection was carried out on a swine farm in the Carlos Arvelo municipality in the state of Carabobo, Venezuela. The farm presented high levels of liver condemnation at the slaughterhouse due to classical lesions caused by migration of A. suum larvae. In order to achieve this purpose, 525 pigs were sampled in quantitative faecal examinations (Mac Master and Wisconsin techniques) and 40 intestinal tracts were collected at the abattoir for precise assessment of A. suum burdens. The following results were obtained: the observed prevalence was 22.66% for coprological examinations and 68,29% for worm recovery. Spatial disposition of eggs on feces rind worms recovered was in aggregates. Cases of infection were prevalent and observed during growth, 31.43%; in replacement gilts, 53.33% and during fattening, 75.73%. The fattening period showed the highest number of eggs per gram of feces (e.p.g). Infection intensity during growing and fattening was light and, in some cases, moderate and independent of sex. There were no quantitative and significant correlations (P <= 50.05) between: A. suum burden and e.p.g count, female and male burden, female and e.p.g count. Furthermore, it was observed that a small numbers of pigs were false positive. The monthly variation index showed that for this farm liver condemnation occurred during the entire year as consequence of favorable climatic conditions for Asuum infections.