Why your pregnant cow can easily die if left lying on left side

A farmer with her cow and one-month-old calf. In most cases, pregnant cows are diagnosed with milk fever if they go down and are unable to stand. Photo/NMG photo

What you need to know:

  • Those conversant with global warming discussions have heard that cattle are some of the drivers of climate change through production of greenhouse gases.

In many situations, pregnant cows are diagnosed with milk fever if they go down and are unable to stand. That is, however, not always be the case. The animal health service provider needs to evaluate the recumbent cow carefully and determine the cause of the problem.

It may be more than one cause that downs the cow, the progression of damage from the initial cause or even a development that arises from a faulty biological process.

Calving down 
Last Sunday, my plans of a good rest were scattered by a call from a farmer. The farm manager, said a cow that was to calve down in about a week had gone down at night.

The team had tried to make the cow stand to no avail. Initially, the animal would put some effort to stand but the legs were weak. They kept folding backwards at the joint above the hoof.

After a few attempts to get the cow to stand, it gave up and kept complaining with a low grunt every time the team made an effort to raise it up. The animal was calving for the first time.

I informed the farmer manager to let the animal lie on its sternum. I would be on the farm within the hour.

I was just starting up the car when the manager called again and said the cow was lying on the side and the abdomen was heavily swollen.

The cow was grunting loudly and its eyes were protruding. He said it looked like the animal would die before I arrived. On further questioning, farm manager told me the cow was lying flat on the left side and the anus was protruding prominently.

I instructed him and his team to quickly turn the cow to lie on the right side while keeping his phone on. I heard the animal belch heavily and release a loud breath.

The farm manager confirmed that the cow now looked comfortable and the abdominal swelling had subsided rapidly.

I told the manager to ensure a cow that is down always lies on the right side or on the brisket. It should never be made to lie flat on the left side.

Normal cows 
When cows are normal, we may not appreciate the amount of gas they produce in their largest stomach compartment called the rumen.

Those conversant with global warming discussions have heard that cattle are some of the drivers of climate change through production of greenhouse gases.

The innocent-looking animals produce large volumes of methane and other gases in the rumen as they digest plant material. The rumen is on the left side of the cow’s abdomen.

For it to operate properly, it moves to mix the food material in it two to three times every two minutes. The movement expels the gas through the mouth via the oesophagus.

When a cow lies on the left side and cannot turn itself, the rumen is prevented from moving and expelling the gas in it.

The gas builds up, swells the abdomen and compresses the lungs, making it difficult for the cow to breath.

It also compresses other abdominal organs and causes the anus to protrude outward. The gas build-up is called bloating.

For a cow that is down on the left side and bloating, death may be quick if the animal is not righted up. The death is due to poor oxygen supply to the brain because of the compressed lungs.
I arrived on the farm and found the cow down but looking fairly okay. It was even attempting to eat.

The muzzle was, however, dry indicating milk fever. The temperature was normal but heartbeats were weak. Rumen movements were also weak and produced faint sounds.

Rumen movement 
In a normal cow, rumen movements are strong and sound like thunder when the doctor listens to them through a stethoscope.

I noticed the hind quarters of the cow were relaxed. The gluteal or buttock muscles were prominently sunken and felt jelly-like when pressed. The vulva was enlarged and relaxed.

I informed the farm manager and his team that the signs observed with the vulva and hind quarters clearly indicated the animal was ready to calve down. It was the milk fever that had stagnated the delivery process because calcium is important in causing muscle contraction.

Milk fever is caused by a failure in the regulation of calcium in the blood. I quickly gave the cow half a litre of calcium solution into the jugular vein.

The muzzle became wet, the heartbeat became strong and the rumen started moving normally with its characteristic thunder sounds. I picked the heart and rumen changes with a stethoscope.

The cow also started labour pushing and turning the head to look at its back. Nothing, however, came from the vulva except some clear mucous.

I examined the animal through the rectum with my hand. The foetus’ front hooves had moved past the rim of the pelvic canal but the head was stuck in the rim. I pinched the foetus but it did not respond with any movement. I concluded the calf was dead and I had to remove it.

I washed the back area of the cow and disinfected with an iodine solution before inserting my fully gloved hand into the birth canal. To my surprise, the calf withdrew its hooves when I touched them. The calf was alive after all.