Causes,
Symptoms and Prevention of Hardware Disease
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by Barry Lambert
Cattle are unlikely to notice foreign objects as they ingest them.
They chew feedstuffs just long enough to coat them with saliva, form
a bolus, and wallow. When a piece of wire, nail or other metallic
object is accidentally ingested by cattle it tends to be retained
in the reticulum because of the reticulum’s “honey-comb”
shaped lining. Objects that puncture the reticular wall allow leakage
of rumen fluid into the body cavity, and can even puncture the diaphragm,
leading to potentially more severe problems. Such as the formation
of abscesses and adhesions.
The reticulum is situated alongside the diaphragm. Damage to the diaphragm
can lead to respiratory problems. Metallic objects that puncture the
reticular wall and diaphragm can cause significant health problems
to the affected animal and may result in death.
Hardware disease is often viewed as a disease primarily affecting
dairy cattle, but beef cattle are equally susceptible. Feeder calves
may be slaughtered before the disease is detected. Cows are curious
by nature, they explore the world with their mouth and tongue. Areas
having abandoned farm houses and barns can be especially problematic
for feeder or grazing cattle.
Another source of foreign objects are those accidentally mixed into
feeds or bailed into hay. Many feed mixers have magnets installed
in them to remove metallic objects during mixing. Likewise, may feed
mills pass feeds through magnetic fields to minimize foreign objects
in their products.
The symptoms of hardware disease vary depending on the size and type
of foreign object, as well as the site of penetration of the reticulum.
Many times the symptoms are difficult to notice at first. Cows may
simply decrease feed intake, or begin to lose body condition slowly
over time. In more obvious cases, cows may be reluctant to move, get
up and/or lay down. Cows suffering from the disease are often seen
standing with an arched back and when forced to walk or move, may
grunt in discomfort. They may also show signs of pain during urination
and defecation. The vagus nerve carries neural signals from the brain
that control ruminal contractions. If the puncture and associated
inflammation apply pressure to the vagus nerve, ruminal contractions
may be impaired. When this occurs, cattle will often bloat because
one important function of ruminal contractions is expulsion of gases
from the rumen.
Another important function of the contractions is to move feedstuffs
out of the rumen to the lower digestive tract. When ruminal contractions
are impaired, cows often show decreased feed intake due to lack of
movement of feedstuffs out of the rumen. If the object penetrates
the diaphragm and heart, the brisket area of the cow may appear flabby
due to collection of fluid in the chest cavity, or the cow may die
suddenly due to heart failure.
Your veterinarian should be consulted when treating animals suspected
to have hardware disease. Results from specific laboratory tests may
be needed to make a diagnosis. Treatments options generally depend
on the value of the animal and the perceived state of the disease.
Treatments range from antibiotic therapy to surgical removal of the
foreign object. By the time symptoms are noticed and surgery is performed,
the object may have been degraded by the body, making surgery unnecessary.
Antibiotic therapy is generally assumed to improve chances of recovery
from near 50 percent to 80 percent.
Several companies market rumen magnets specifically designed to decrease
hardware disease related problems. They are administered orally with
a balling gun just as you would an aspirin bolus or other medication.
The magnet, which is retained in the reticulum, will hold metallic
objects (at least those that stick to a magnet) decreasing their chances
of puncturing the reticular wall. Consult your veterinarian to discuss
the usefulness of magnets. ©
