As anyone with small kids probably knows, children eat the damnedest things. Perhaps we can still remember this compulsion. Did you ever pick up a bright, shiny new penny when you were young, and have the urge to pop it in your mouth? How about a gum wrapper?
How about a nail?
Hardware disease may sound like something that is more likely to happen to a computer than a living, breathing animal, but happen it does. Never far above children on the intelligence scale, cows are at the mercy of any and all pointy objects left in the path of their less-than-gourmet palate. Let's take a look at the makings of a really bad tummy ache.
The small beginnings of a big problem
Hardware disease is also known as traumatic reticuloperitonitis or traumatic reticulopericarditis, depending on its localization. The path of this condition can be traced in the same manner as any other bovine-ingested material. As large ruminants, most cattle are not particularly discriminate eaters. Unlike smaller ruminants, they do not utilize their lips for prehension and often eat mouthfuls of material without much care or deliberation. They may swallow material nearly whole, only regurgitating that which size dictates needs to be re-chewed. Unfortunately for the bovine in question, this indiscriminate eating may introduce foreign bodies into the stomach. Often, this is in the form of missed pieces of baling wire left on hay, metal shards in silage or hay, or nails, staples and other debris left from construction or machinery in a pasture. As the vegetation goes, so goes the metal.
In some cases, metal may be ingested and never cause a problem. These pieces are often heavy and blunted and therefore pose no threat to the gut. They merely settle to the bottom of the giant fermenting vat that is the rumen. This may be an important consideration for treatment. However, not all threats are so easily contained. Pieces of ingesta that pose a serious risk include all things sharp and/or pointy, especially nails and wire. These pieces will travel from the rumen into the reticulum. Here, they will be sorted out by size, much like other foodstuffs. However, unlike overlong stems of hay, metal will remain in the reticulum, possibly irritating and damaging the mucosa. If the piece of metal perforates the wall of the reticulum, it will cause an inflammation in the peritoneum – thus, the name of the disease. The “pericarditis” comes in when the offending object penetrates the wall of the reticulum near the pericardial sac. Just for overkill, the hardware can penetrate this as well and cause more irritation and inflammation. Less than ten percent of cows that are affected by hardware disease will have pericardial involvement.
The fate of a metal-studded cow is not set in stone. Those that ingest objects and never show signs are said to be sub-clinical cases. There may also be a chronic issue, which presents in a different manner than acute hardware disease. It has been suggested that internal pressure, and certain conditions that cause an increase in internal pressure, may be to blame for pushing the foreign bodies in to and ultimately through the reticular wall. These include tenesmus and an occupied uterus, and may be predisposing factors for acute hardware disease presentation. Generally, this is a disease of dairy cows and other animals that will survive for longer than two years of age.
As stated above, sub-clinical disease will never show signs or symptoms.
Signs of chronic disease include:
Acute disease presentation is that of acute peritonitis, and includes:
Differentials for hardware disease include:
Several tests are indicated under suspicion of hardware disease, in order to help distinguish it from other conditions with similar presentation. A complete blood count can indicate an acute or ongoing inflammatory response. In acute phases of the condition, animals may show no differences in cell count, but have high levels of fibrinogen. Other animals will have a definite left shift in neutrophils. This indicates that many immature neutrophils have entered the circulation, due to the body's increased need for inflammatory cells. Chronic conditions will often present a mature neutrophilia, as well as a lymphocytopenia. However, the CBC does not represent a diagnosis for the condition. This presentation is very similar to any intense inflammatory process in cattle, so further tests must be conducted.
A serum biochemistry profile may be used to check for other imbalances in the body. The most telling alteration will be a increased amounts of protein and globulin in the blood. A very strong correlation between hyperproteinemia/hyperglobulinemia and hardware disease exists – one study showed that 83% of cattle with total serum protein at or above 10 mg/dL were suffering from hardware disease. Other blood findings are usually peripherally associated as sequellae from symptoms such as rumenal stasis. Secondary serum findings may include:
Finally, abdominocentesis may be utilized to check the abdomen for fluid consistency. Normal abdominal fluid is usually free of leukocytes, other nucleated cells, and is straw-colored and clear. If peritonitis is present, the fluid will become turbid and may contain fibrin, cells or cellular debris, which are indicative of a purulent disease. However, “normal” findings in the fluid does not rule out a peritonitis, as the body will usually try to contain disease in a localized area. Performing the procedure at the rumenal-reticular recess will increase the chances of entering a contained infection, if one exists.
Other slightly less invasive methods of diagnosis include ultrasound and x-ray measures. Ultrasound can be used to look for fluid in the abdomen, lungs, or pericardium. X-ray can be used to locate and visualize the actual piece of hardware. Unfortunately, many pieces of metal may not be dense or large enough to be seen well, and both pieces of machinery are cumbersome and somewhat difficult to operate in a field setting.
Treatment for hardware disease is somewhat unspecific. The best method of treatment seems to be prevention. To this end, any cattle are outfitted with rumenal magnets. These magnets are administered orally, like a pill, so that they can settle in to the bottom of the rumen like any other large piece of metal. Here, they will collect and hold offensive bits of metal in an effort to prevent them from causing damage. Magnets are generally three to four inches long and ½ to ¾ inches in diameter. At a cost of less than $10 and a wide availability through both feed stores, veterinarians, and slaughterhouse recovery, these magnets are the logical and inexpensive choice for preventing a possible catastrophe.
If prophylaxis is not used, or has failed, magnets may be administered after the fact orally in an effort to pull metal back to the bottom of the rumen, allowing the reticulum to repair itself. Antibiotics are often given in an effort to control peritonitis and the reticular abscesses that may follow trauma. Antibiotic use in cattle is often difficult, as it interferes with proper rumen flora, and also has implications for the sale of meat harvested from the treated animal. In some instances, surgery is required to remove the piece of debris. This may be too invasive and costly for cattle that will not recoup value after the procedure, and may not be undertaken for all animals.
Hardware disease is a constant danger, even though it is not an infectious disease. In some environments, large portions of a herd can be affected. Through a mostly intuitive treatment plan, the issue can be controlled in most situations. Hopefully this has given to a little sharper insight into just another issue that your local cattle farmer has to deal with. Help be part of the solution by making sure to never litter areas where cows might roam with metal or items with perforating potential.
- http://www.caf.wvu.edu/~forage/hwaredis/hwaredis.htm
- http://www.vet.uga.edu/VPP/clerk/caveto/index.php
- http://en.wikipedia.org/wiki/Hardware_disease
- http://www.press-enterprise.com/newsarchive/1999/09/25/938237021.html
- http://www.magnetsource.com/Solutions_Pages/cowmags.html
- http://gpvec.unl.edu/StudentRounds/quiz/050799.html
- http://www.ncbi.nlm.nih.gov/pubmed/13462898
- http://www.cvm.tamu.edu/acvp/hardwaredisease/hardware.htm
Shaogo adds: You forgot to describe the "other" hardware disease: shaogo in a Home Depot store with a high-limit credit card...