Causes, Symptoms and Prevention of Hardware Disease

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.