Late in August a veterinarian was called to a farm to attend a dystocia. On arriving he found a Brown Swiss cow trying to have her second calf. The fetus was in normal anterior presentation with the forelegs and head protruding from the vulva. The eyes were open and the calf was apparently in good condition. After repelling the calf, the birth canal was palpated but nothing could be felt. The assistant then pulled the fetus out as far as possible and in this position a greatly distended sac of fluid was felt just over the rim of the pelvis. This was an enormously enlarged abdomen.