An internal catheter has a flexible plastic inner tube with an integrally formed protruding head with an axial channel. The internal catheter extends through an axial channel in an exterior catheter. With the internal catheter head withdrawn within the foam or spiral tip of the exterior catheter, the assembly is advanced into a sow cervix, and the internal catheter is then advanced through the tip of the catheter and remaining portion of the cervix and into the uterine body and possibly into a uterine horn. Semen or embryos are then introduced through the axial cavity. The tip of the exterior catheter may have a protective flap which is not penetrated until the inner tube is advanced therethrough. The internal catheter axial channel may have a constricted portion within the head, to engage a semen or embryo containing straw.