Published online by Cambridge University Press: 06 April 2009
The growth of Hymenolepis microstoma in weanling (21–23 days old) and adult (> 10 weeks old) rats has been investigated. Growth proceeded normally until the worms were about 9 days old. They then destrobilated, leaving only the scolex attached to the duodenum or bile duct. In only 1% of the rats did growth of the worms continue beyond 10 days and these large worms caused the bile ducts of their hosts to become distended. Immuno-suppressants had no effect on the growth of the worms, and tests suggested that there was no serological reaction to infection. It was concluded that the rat is a poor host for Hymenolepis microstoma but that it is not completely refractory.