Experimental infection of laboratory animals and sheep with Gongylonema pulchrum in Japan

Japanese White rabbits, Wistar rats, ddY mice, Suffolk sheep, and a domestic cat were each orally inoculated with 20-140 third-stage larvae (L3) of Gongylonema pulchrum, isolated from naturally infected dung beetles captured in Aomori Prefecture. Worm recovery rates were 40.0-72.0% in rabbits at 7, 14, and 19 weeks post-infection (PI) and 3.3-25.0% in rats at 19 weeks PI. Those in 2 sheep at 7 weeks PI showed 53.6% and 29.3%. No worms were recovered from the mice and the cat. In the susceptible animals, many worms were found in the esophagus, and a few were present in the pharyngeal mucosa, tongue, buccal mucosa, and cardiac portion of the stomach wall. No distinct morphological differences were observed in the worms from rabbits and sheep. These results indicate that rabbits are very suitable experimental definitive hosts for G. pulchrum.