Ascaris suum prevalence and intensity: an abattoir survey of market hogs in Saskatchewan.

Two surveys examining the prevalence and intensity of Ascaris suum were conducted at a Saskatchewan abattoir. In the first, 2500 livers from market weight animals were examined and scored for lesions consistent with ascarid migration. Forty-four percent displayed some degree of scarring with approximately 8% being severely damaged. In the second, both livers and intestinal contents from 500 market weight animals were examined. Seventeen percent were infected with intestinal A. suum (mean of 2.5 parasites per infected pig) and 50% had liver lesions typical of ascarid larval migration. Fifty-three percent of the animals in the second survey had some evidence of ascarid infection (adult parasites, hepatic lesions or both). The results are compared with those from a similar survey conducted in the late 1970s at the same abattoir as well as with surveys conducted elsewhere in Canada and in the UK.