Hong C C, Ediger R D, Djurickovic S
Lab Anim. 1977 Jul;11(3):189-91. doi: 10.1258/002367777780936710.
A case of opocephaly in inbred guinea-pig strain 2/N and another in strain 13/N, a conjoined twin and an opocephaly concurrent with conjoined twins in the Dunkin-Hartley/FD strain are described. The incidence of congenital malformations in the inbred strain 2/N and strain 13/N was 0-0013 and 0-0073% respectively. The incidence in the random-bred Dunkin-Hartley/FD strain was 0-0007%.