Last week we discussed cardiac issues in horses. This week, I’d like to explore the bovine heart.
Rarely do I suspect heart conditions in cattle. If I do, it’s secondary to gastrointestinal issues. The reason behind this is a cattle-specific condition commonly called hardware disease.
Hardware disease, medically known as traumatic reticuloperitonitis, is due to the fact that cows tend to resemble me on Thanksgiving; that is, they eat like a vacuum cleaner. When cows come up to a feed bunk after grain has been poured in, their prehensile tongues lick and grab anything in there, be it soybean hulls and corn silage, or the occasional nail, screw, bolt, or piece of metal wire that has inadvertently fallen in. Once consumed, these pieces of metal get jostled around in the rumen, then work their way into the cow’s second stomach, the reticulum.
For some anatomical reason, metal objects like to hang out in the reticulum instead of passing through the rest of a bovine’s gastrointestinal tract. This, as you can imagine, can cause problems. If the object is pointy enough (pointy being a medical term), it can penetrate the wall of the reticulum and work its way out into the abdominal cavity. The body, understandably, doesn’t look kindly on this and massive localized infection and inflammation accumulates, resulting in a sick animal.
So how does the heart get involved? It turns out a cow’s heart sits right next to the reticulum, separated only by the thin muscular diaphragm that partitions the thorax from the abdomen. Sometimes, if the metal pointy object is long enough, it will poke through the reticulum, through the diaphragm, and start to poke the heart. Naturally, this has consequences and results in a condition called traumatic pericarditis.
As infection and inflammation gather around the heart, fluid begins to accumulate in the pericardium, which is the membranous sac that encases the heart. At this point, it is very hard to turn the disease around. Large doses of antibiotics rarely are enough to overcome the infection that has migrated from the intestinal tract to the heart. Pericardiocentesis, which is the draining of pericardial fluid with a needle and syringe, usually doesn’t help in the long run, either. Most cows with traumatic pericarditis are euthanized.
However, if I suspect a cow might have hardware disease of the non-cardiac variety, there’s a simple thing I do: orally administer a magnet to the cow. I know it sounds crazy and more than a little old-fashioned, but a magnet will follow the route of the offending object into the reticulum and help attract the metal object away from the wall of the organ. Many knowledgeable farmers will prophylactically administer magnets to cows that seem to have a gastrointestinal disturbance. Funnily enough, the magnet will sit in the reticulum even after its job is done, thereby acting to prevent future foreign metal objects from causing problems.
Hardware disease (without cardiac involvement) is one of my favorite cattle diseases because of its treatment: so basic and logical, and yet at first thought, is seemingly unrealistic. Can you imagine the first person who suggested giving a cow a magnet? I imagine that conversation as starting, “You know, this may sound crazy, but it just might work…” How many medical problems over the course of history have been solved with such thinking!
Dr. Anna O'Brien