The challenges of a difficult calving
Published 01/02/2012 | 06:00
The spring calving is well upon us here in the north east and with it comes the usual difficult cases. We had a cow with twins presented last week with four legs and no head in the birth canal. These can be quite difficult to rectify, especially in small heifers with a very narrow opening.
It's the study of anatomy that comes into major play with these cases as we try to follow each limb back to each calf. At first, it's a case of determining if the foot is a front or back leg, and then which pair of feet belong to one calf and which pair to the other.
A very long arm is a huge help in these cases, and at all times the vet must be absolutely certain the correct feet are attached before beginning to pull the calf. Often with twins one calf is coming backwards, and every care must be taken not to catch the umbilical cord as the calf is being pulled out.
With a different case in early December, we had a fine Limousin cow presented with the calf coming backwards. It was a single calf and the mother was reasonably wide behind. She had been calving several hours with feet protruding for more than two hours, but with no further progress. On handling this case everything was as it should be, and initially we wondered why the cow was not getting on with her business. But very quickly it became apparent that the umbilical cord was caught around one of the hind legs.
The umbilical cord usually becomes entrapped in the last few days and hours of pregnancy when the calf is repositioning itself to enter the pelvic canal. Quite a deal of movement goes on just before the onset of labour. If the calf is presented backwards and is lying on its side or back in late pregnancy, it has to roll over to present correctly as the calving process starts.
As he rolls over, the umbilical cord, which is very close to the hind legs, can end up between the two back legs just as the calf is ready to move out into the birth canal. Now if the cow pushes or we pull, the cord will come under immediate pressure and break well before the calf is even a quarter way out.
That's his oxygen source cut off and now he takes his first breath. There is no air in the womb so out comes a dead calf after all the huffing and puffing. To avoid this, the vet must try to get the offending leg back around the cord to free it before pulling the calf out backwards.