Points that should be kept in
mind in reaching a decision in regard to the acquisition of germ free or
SPF guinea pigs are that: a) the expense and difficulties in setting up a
gnotobiotic guinea pig breeding colony can only rarely be justified when
these animals can be acquired commercially (NRC U.S., 1979); and b) the
option of obtaining the required germ free animals by hysterotomy from
healthy dams from the conventional colony should be seriously
considered. Isolator raising of caesarian derived, germ free guinea pigs is
made relatively easy by their precocity (NRC U.S., 1970).