Method for chronic catheterisation of the amniotic sac in cattle

The chronic catheterisation of the amniotic sac of eight pregnant cows of 180 to 200 days gestational age is described using an indwelling catheter of polyvinyl tubing. Although strict asepsis was followed, the main problem encountered was preventing contaminant bacteria from overwhelming the fetus, causing its death. This was successfully achieved in four animals, three of which received a mixture of ampicillin and cloxacillin sodium intra-amniotically and parenterally in the dam. Daily sequential samples of amniotic fluid were readily obtained until just before fetal death.