Some characteristics of a laboratory produced strain of Oesophagostomum dentatum

Abstract

The isolation of Oesophagostomum dentatum from pig is described, and several morphological characteristics of the parasite and some special features about its life-cycle are illustrated and discussed. Ninety-eight female worms with a tail-length of about 350 μm were isolated from one sow. The eggs were separated from the uterus and transferred to a culture medium. The infective larvae obtained were fed to a Vietnamese miniature pig. As a control for the species isolation, a Belgian landrace pig was infected with 2000 L 3, which had originated from the Vietnamese pig. Eight weeks later the control animal was slaughtered; the tail-length of 200 female worms isolated was measured. The measurements showed a symmetric and normal distribution with a mean of 313.23 μm. Five three-month-old sows were each infected orally with 50 000 O. dentatum larvae. The prepatent period was found to be between 26 and 28 days. The egg-counts fluctuated widely and after killing the pigs only a small number of mature worms were found to be present. Histological examination of the mucosa of the intestines did not show a prolonged histotropic phase. Two hundred worms from each pig were measured, and the lengths were 8.72 to 10.83 mm for females, 7.70 to 8.74 mm for males. The length of the spicules ranged from 1004 to 1043 μm, and the tail-length of the females from 299 to 18.75 μm. Only the measurements of the tail-length belonged to a symmetric population. The adult worms had a buccal capsule with parallel sides and a club-shaped oesophagus.