This is a relatively common disease affecting adult cows in this country. It has many names, also being called foreign body reticulitis, reticuloperitonitis and reticulopericarditis depending on the exact presenting signs.
In all cases, the affected animal has eaten a foreign body, invariably a piece of wire, which has become embedded in the wall of the cow’s reticulum (second stomach). The outcome depends on whether the wire is released from the wall or progresses to fully penetrate the wall of the stomach.
It is normally the wire found in tyres, used in the covering of silage pits, that causes the problem. If old rotting tyres are used, there is a much higher risk of bits of exposed wire cracking off and falling into the silage, which subsequently gets eaten by the cow. The length of wire that causes a problem is also quite predictable, most offending foreign bodies being 6-8cm in length.
The symptoms of Hardware Disease depend on where the wire penetrates through the wall of the reticulum. If the wire penetrates through the side, there will be leakage of stomach contents with abscess formation, adhesions and peritonitis. The adhesions usually lead to shutdown of the forestomachs of the cow, and the condition of vagal indigestion, which is usually fatal.
Cows with reticuloperitonitis have an arched back due to pain in the front of the abdomen, and they will often grunt when the withers is pinched. They usually have a stiff gait with shortened strides. If they develop vagal indigestion, the cow will show a progressive swelling of the abdomen as the stomachs fail to empty.
If the wire penetrates the wall of the reticulum at the level of the elbow, it usually passes forward through the diaphragm (the muscle that separates the chest from the abdomen) and into the pericardium (the lining surrounding the heart). This sets up a severe infection within the pericardium pericarditis), which compresses the heart, leading to congestive heart failure. In these cases, abdominal pain is also accompanied by distended jugular veins in the neck and the build-up of oedema fluid under the jaw and mat the brisket.
In most cases, a veterinary practitioner will be able to diagnose this condition based on clinical signs. The cases involving the heart will have muffled heart sounds which can be picked up on auscultation by the vet. In cases of vagal indigestion, there are other causes that must also be ruled out.
Post-mortem examination will reveal the presence of the wire in the reticulum and the associated peritonitis or pericarditis. An x-ray of the reticular area can be used to detect a wire in referral facilities such as the UCD Veterinary Hospital.
In general, the prognosis is very poor with this condition. In the early stages of a reticuloperitonitis, a long course of antibiotics may help to wall off the infection and the cow may continue in production.
Similarly, surgical removal of a wire in the early stages of disease, together with antibiotics such as penicillin or amoxycillin, may occasionally have a successful outcome. Specifically designed magnets may be given as boluses to cows with suspected Hardware Disease in order to try to trap the foreign body and prevent it from migrating through the stomach wall.
If heart failure or end stage vagal indigestion occurs, the prognosis for treatment is hopeless.
This disease can be prevented by reducing the risk of cows being exposed to feed that could potentially contain foreign bodies. Old, rotting tyres should be discarded and not used on silage pits and old, unused fencing wire should be stored away from the vicinity of feed.
In some herds, where there are ongoing cases, it is advisable to dose all cows with magnets as a preventative measure.
*This article previously appeared in the Irish Farmers Journal on 16 July 2011 as part of a series on animal health.