When it comes to eating, cattle don’t usually sort their food, which means they can ingest foreign matter when eating hay or processed feed. Among that foreign material can be metal objects, such as pieces of wire, nails, or metal flakes from feeding equipment. These objects generally settle into the reticulum to cause what’s called “hardware stomach.”
Once ingested the cow’s digestive contractions can push these sharp objects through the stomach wall, into the abdomen, chest cavity, even the heart. Medical terms for hardware disease include traumatic reticulo-peritonitis or traumatic reticulo-pericarditis, depending on where the object travels.
Andrew Niehaus, Ohio State University assistant professor of farm animal surgery, says hardware stomach is a continuum.
The result of ingested metal can be as benign as reticulitis if the object only lodges in the reticulum where it causes irritation, he says. Because the object doesn’t puncture the wall, these animals may have “off” days when they suffer a little gastrointestinal pain, but they aren’t sick, he says.
“The next step in seriousness is when the object pokes through the wall of the reticulum and goes into the abdomen, causing contamination and peritonitis,” he says. But it also may go farther and penetrate the heart.
“The reticulum is next to the diaphragm, and on the other side of the diaphragm is the heart. If the metal pokes through into the pericardial sac around the heart, the cow becomes very sick, with signs of heart failure.”
One of the major risks of hardware stomach comes with parturition. A piece of metal may not be problematic moving around in one of the cow’s stomachs, or walled off in a local abscess. But during late pregnancy, the distended uterus can put pressure on the reticulum or disturb walled-off infections. Once in labor, the pushing to give birth may break old adhesions loose or push a wire through the stomach wall.
The reticulum is next to the diaphragm and, as the cow strains to deliver her calf, she may push an object into the peritoneum, or through the diaphragm. “This is when a mild problem becomes a bigger problem,” Niehaus says. If a cow does poorly after calving, hardware may be the cause.
Symptoms & diagnosis
David Steffen, a DVM with the University of Nebraska’s Veterinary Diagnostic Center, says signs of hardware stomach aren’t specific.
“If the cow has a localized abscess or mild peritonitis, she goes off feed and looks dull, but these signs could also be indicative of several other diseases. By the time she shows signs of heart failure, the heart sac is severely damaged and it’s too late,” he says.
Matt Miesner, Kansas State University assistant professor of agricultural practices, says signs of hardware stomach can appear quickly, slowly or intermittently. Cattle with a foreign object poking into or through the stomach wall may be humped up from internal pain.
“The cow eats less, and drops in milk production, so her calf may not be doing well, either. In addition, we may see signs of heart problems, and the jugular vein may be distended. The cow may appear to have a respiratory problem, breathing fast and shallow,” Miesner says.
Such symptoms may be mistaken for respiratory disease, especially if she’s going into heart failure, Miesner says. In fact, some cases look like high-altitude disease because there’s so much edema in the brisket, and the jugular veins are huge.
“The animal’s fever isn’t usually very high – maybe 104-104.5 F. If a rancher treats with antibiotics, it may help for awhile, but she still isn’t doing well. By the time the veterinarian is called, signs may still be vague,” he says.
As magnets are often bolused into the cow’s stomach as a preventive measure to collect foreign metal material, an attending veterinarian may use a compass to see if the cow has a magnet, Miesner says.
“The veterinarian also may pinch the cow’s withers. Most cattle, if their withers are pinched, will sink down to get away from that irritation. But if they have lower abdominal pain, they won’t sink down because that would hurt more. Instead, they may hump up.”
Another diagnostic technique is for two people – one on each side of the cow – to press a bar or board upward against the cow’s sternum. “Sometimes you have to listen to the airway with a stethoscope while this is being done, but this upward pressure makes the cow grunt,” Miesner says.
Most veterinarians don’t x-ray a cow due to size limitations, but ultrasound can be useful, he adds.
“I place an ultrasound probe on the cow’s chest or sternum, which may allow me to see some pus around the reticulum. I can see the rumen moving or if it’s ‘sticking’ because of infection and adhesions,” he says. If there’s an adhesion, the animal may be prone to bloating, and may not be chewing her cud.
Prevention & treatment
The most important step in prevention is to keep wire and metal objects out of feed. Feed-delivery systems should have magnets on conveyer belts to capture metal. And feed conveyers should be checked frequently to make sure their magnets are clear and able to operate.
In addition, work to keep hayfields as “clean” as possible. And, be careful when swathing or baling along a fence that might have broken wires out in the field that a swather or baler might chop up.
Niehaus recommends giving cattle magnets. “In a cow-calf operation where cattle aren’t being fed a total-mixed ration, it’s less likely you’ll have problems, unless there’s wire chopped up in baled hay.”
But if a cow seems a bit “off” and you suspect she might have ingested foreign material, a magnet is a good idea. This might help keep a piece of metal from penetrating through the stomach wall, Niehaus says.
“Some farmers and ranchers routinely give magnets as a preventive, or put one into any cow that starts showing signs akin to hardware disease,” Miesner says. Inexpensive magnets are available for as little as $2, but it’s a preventive step rather than a treatment, he says.
Miesner says the traditional wisdom held that any cattle with magnets should be identified to avoid inadvertent administration of a second magnet. The thinking was that two magnets in the reticulum might line up and cancel each other out, he says.
“We hear this a lot, but I’ve put them side by side on my desk and they still attract and collect metal pieces. But if you want to check cattle for magnets, use a compass.”
If a metal object is just starting to poke into the stomach wall, a magnet may pull it back and hold it. “Once it goes through the wall, however, there’s no way to get it to come back. But as the stomach contents churn around, the magnet may attach onto metal and keep bringing it back away from the wall,” he says.
Niehaus says surgical retrieval of metal usually involves an incision in the cow’s left flank, using the rumen as a window to gain access to the reticulum.
“We do standing surgery (similar to a C-section), and pull the rumen next to the skin so we can suture it there. This forms a seal so there’s no chance of getting rumen fluid into the abdominal cavity,” he explains.
“Anything in the reticulum or embedded in its wall theoretically should be retrievable, though this can be challenging. Even if you can reach the reticulum, the honeycomb-shaped pockets in the walls can trap and hide a small object. For instance, the head of a nail, with the rest of the nail already poked through, may be hard to feel,” Niehaus says.
If a magnet is present, he pulls it out. “There may be metal pieces stuck to it. When I’m done with surgery, if the magnet I’ve taken out and cleaned is still good, I drop it back into the reticulum. If there was no magnet, I put one in,” he says.
Recovery by cows following surgery varies. “If the infection isn’t too severe or widespread, a cow has a good chance. We get the wire or nail out and put her on broad-spectrum antibiotic. But if she has severe peritonitis, with lots of abdominal contamination, she won’t do well. And, if there’s pericarditis (inflammation or infection around the heart), prognosis is poor,” Niehaus says. “This is definitely a disease where an ounce of prevention is worth a pound of cure.”
Sidebar: Risk factors
The overwhelming majority of “hardware” ingested by cattle consists of wires 2-5.5 in. long.
“Shorter pieces may pass through the stomachs without causing a problem. Cows can ingest fence staples, barn nails, bits of wire or any other objects that find their way into feed; that’s why fathers yell at their kids to pick up nails and staples,” says David Steffen, a DVM with the University of Nebraska’s Veterinary Diagnostic Center.
Cattle can chew the ends of baling wire used to fasten panels to fences, for instance. In addition, there may be nails, roofing tacks and other metal objects around a barnyard or junk pile where cattle graze. In feedlots, metal pieces come off feed-handling equipment and get mixed with feed.
“Another name for hardware is tire wire disease,” adds Matt Miesner, Kansas State University assistant professor of agricultural practices. “A frequent problem in the 1990s was ingestion of wire from old tires used as feeders or for holding down tarps on silage or feed piles,” he says. Over time, tires decay and the rubber disintegrates, exposing wire reinforcement. Those small wires may break up and get into the feed.
Knives or cutting blades in a mixer can wear out and fall apart, with bits and shards breaking off and going into the feed. Strong, heavy magnets on feed conveyers usually catch those, but they must be checked frequently to make sure they’re capable of attracting and holding metal pieces.
In addition, cattle are sometimes put into situations that make them vulnerable to hardware. During a drought, for instance, cattle may graze vacant lots, or people cut and bale grass along a roadway or other areas that generally aren’t grazed or baled. There may be junk piles or litter, loose bits of wire or other discarded objects.
Sidebar: Metal’s not always the culprit
Occasionally, some other type of object – even a sharp rock – may penetrate the stomach lining and cause peritonitis or damage the heart.
One rancher tells of a cow that suddenly showed signs of acute hardware disease and heart failure in late winter. She was humped up, reluctant to move, trembling and staggering; she died quickly. Upon necropsy, the veterinarian found a small, flinty rock of the shape and sharpness of an arrowhead that had gone through the lining around the cow’s heart.
The day before the cow died, the herd had been moved to a different field, traveling across a driveway where hay had been spilled along the edge of the road, on shale-type gravel. The cattle had gobbled up some hay, and apparently this cow ingested a piece of sharp gravel with a mouthful of hay. A magnet would not have helped in this situation.
Heather Smith Thomas is a rancher and freelance writer based in Salmon, ID.