Experimental infection of pigs with Oesophagostomum dentatum: pathogenesis and parasitology of repeated mass infection.

Pigs receiving a limited ration of 1 kg commercial feed per day were infected daily with 50,000 Oesophagostomum dentatum larvae. The animals exhibited serious diarrhoea and anorexia. Although there was neither anaemia nor hypoproteinaemia, there was a significant decrease in plasma sodium and an increase in blood urea nitrogen at the end of the experiment. Large numbers of third and fourth stage larvae were found in the ileal, caecal and colonic mucosae. Only fourth stage larvae, never adults, were observed in the lumen. A continual expulsion of large quantities of third and fourth stage larvae were demonstrated in the faeces beginning with the appearance of diarrhoea. Neither Vibrio coli, Salmonella spp nor Balantidium coli contributed to the course of the enteritis.