Occurrence of Gastrointestinal Nematodes in Pigs in Ibaraki Prefecture

Fecal examination was performed on 1, 012 pigs bred in Ibaraki Prefecture to detect gastrointestinal nematodes. As a result, nematode eggs were found in 132 pigs (13.0%) and the average EPG (eggs per gram of feces) was 85.8. The infection rate in the breeding pigs was apparently higher than in the fattened pigs, the positive rates being 56.2%(59 of 105) and 8.0%(73 of 907), respectively. Three species of nematodes, Oesophagostomum dentatum, Ascaris suum and Trichuris suis, were identified in this examination. Of them, O. dentatum was the most predominant, the positive rate of which was 50.5% in breeding pigs and 2.2% in fattened pigs. The other two species were recorded in less than 6% of the pigs. Accordingly, treatment with anthelmintic to breeding pigs seems to be necessary to reduce the occurrence of gastrointestinal nematodes.