When your cow swallows nails

When livestock especially dairy cattle swallow a nail, it leads to a medical condition called hardware disease.

Hardware disease medically speaking is more of a mechanical injury as it results from ingested sharp objects that pierce the stomach wall through the diagraphm and eventually the heart.

When the heart is injured clinical symptoms become evident but many animals will have these sharp objects but will still be in perfect health as it only becomes a problem after puncturing the stomach wall.

A recent research in eastern America found between 55 per cent and 75 per cent of animals slaughtered had sharp objects in their reticulum but not all showed clinical signs. The cow uses its long tongue to grasp grass, form a bolus covered with saliva and swallow.

Clinical consequences

When at rest, this ball of grass is regurgitated back into the mouth for further chewing a process called chewing the curd.

This manner of eating predisposes the cow hardware disease because it makes it easy to swallow sharp objects like nails, wires and pins. The objects are normally trapped in one of the stomachs, which anatomically are separated from the chest cavity by the diaphragm.

During digestion, the contractions that churn the food can slowly push the object through the diaphragm and into the heart with severe clinical consequences.

Pregnancy also predisposes animals to hardware disease as the reticulum is pushed forward and next to the diaphragm muscular contractions at birth may just give that fatal push to the objects to cause a perforation.

Perforation of the reticulum wall alone will result in leakage of semi-digested matter into the body cavity with subsequent swelling.

The rapture of the diagram alone will result in respiratory problems which can be deadly. When the heart comes into the picture, death due to heart failure can happen.

The clinical signs of hardware disease vary depending on the trajectory of the sharp object and its size.

Nonetheless, the cow can also show nonspecific signs like reduced appetite, low milk production and loss of body weight.

Bloating

The most characteristic signs for hardware disease are an arched back while standing and pain and grunting during defecation, urination or walking down a steep slope.

Sometimes, hardware disease can result in bloating due to injury to the nerve that controls stomach contractions and this can by itself result in death.

When the heart is perforated there will be accumulation of fluid in the chest cavity and loud whizzing sounds can be heard from the chest area.

At diagnosis, a veterinary surgeon will perform a withers test by squeezing the cow’s back just above the withers and listen for the grunting noise due to pain.

In most cases, slaughter is normally recommended but for high value animals and depending on location, surgery can be attempted.

Antibiotic treatment can also be applied to control secondary infection and hope that the metal will rust away and the body encapsulates the metal safely.

Magnets can be administered orally with the aim of holding the metallic object in the reticulum and therefore decreasing its chances of perforating the stomach wall.

To prevent the disease, avoid feed contamination with metallic objects and don’t use old steel reinforced car wheels for watering animals or any other objects with sharp metallic components.

As a preventive measure, the rumen magnets can also be used.

Modern feed mixers and choppers are fitted with magnets fitted on them to attract and retain metallic objects that accidentally find their way into the feeds.