Studies on the Dutch Rabbit for Pyrogen Test

A study was conducted on Dutch rabbits to examine their applicability for the pyrogen test in comparison with the Japanese white rabbit which, conventionally, has been mainly used for the test in Japan. The following results were obtained. Adult Dutch rabbits, so small as to weigh only about 60 % of average adult weight of the Japanese white, showed a food consumption as low as 40 of that in the latter. None in the Dutch rabbit group suffered dislocation of the hip-joint during restraint on a neck stock while it was frequently encountered among Japanese white rabbits. The body temperature during restraint was unstable in infantile Dutch rabbits (7-8 weeks old), but stable in the young (14 weeks old) and in the adult (20-47 weeks old) . Adult Dutch rabbits exhibited greater febrile responses to intravenously injected bacterial pyrogen (LPS) than infantile and young Dutch rabbits and adult Japanese white rabbits. A good linear regression was observed between the dose of LPS (0.01-0.1μg/kg, iv) and the febrile response in adult Dutch rabbits as well as in adult Japanese white rabbits.<BR>From these data, it is concluded that the Dutch rabbit has an advantage over the Japanese white for the pyrogen test in respect of febrile responsiveness and cost of rearing.