I was a vegetarian for most of my life, and it started with hamburger. In middle school, I realized that all of the stringy bits of ground beef that look so orderly and neat at the deli counter could potentially be hundreds of individual cows. Hundreds. I didn’t actually care that much about the well-being of those cows, but there was just something about eating dozens of individuals in every bite that grossed me out, and I didn’t eat meat again until my 30s. I started eating it again last year, after realizing that I’d been hungry for almost two decades, and today I’ll happily consume pork sliders or chicken soup or fish tacos. But hamburgers? None for me, thanks.

Turns out, my early instincts that ground beef is gross were right. According to a new investigation by Consumer Reports, there’s something in your hamburger, and it’s shit.

Researchers analyzed 300 packages of both conventionally raised and grass-fed ground beef purchased from grocery stores, and, they report:

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The results were sobering. All 458 pounds of beef we examined contained bacteria that signified fecal contamination (enterococcus and/or nontoxin-producing E. coli), which can cause blood or urinary tract infections. Almost 20 percent contained C. perfringens, a bacteria that causes almost 1 million cases of food poisoning annually. Ten percent of the samples had a strain of S. aureus bacteria that can produce a toxin that can make you sick. That toxin can’t be destroyed—even with proper cooking.

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The reason for the high rates of fecal contamination is, in part, because there are multiple animals per package of ground beef — exactly the thing that made me give up meat in the first place. Fecal matter from the intestines of one cow gets all mixed up with the rest of the non-contaminated cows and shipped to your dinner plate. And that’s not good. The most famous of these E. coli strains is O157:H7, which can really mess you up. In a history of E. coli outbreaks for Lucky Peach, personal injury lawyer and food safety advocate Bill Mahler writes:

Once this strain of E. coli makes it into our small intestine, it can damage the intestinal wall, causing severe cramping and bloody diarrhea. In some instances, the toxin that the bacteria releases gets into the bloodstream, damaging red blood cells and causing severe complications like kidney failure, stroke, brain damage, and death.

Another issue: drugs. Cows are given antibiotics to both make them grow bigger faster and to prevent infections. Farmers are only supposed to give cattle antibiotics when they are sick, but this is a new rule, and it’s unclear how much it’s cut back the use of drugs. The routine use of antibiotics leads to bacterial resistance. The resulting superbugs could literally kill you if you find yourself with a terrible infection that doesn’t respond to antibiotics. As Mother Jones’ Tom Philpott explains:

The bacterial implications of beef production practices really emerged when the researchers tested the bacterial strains for resistance to antibiotics. Nearly a fifth of conventional ground beef carried bacteria resistant to three or more classes of antibiotics—more than double the number found in the “more sustainably produced” samples, and triple that found in samples from cows raised outdoors on grass.

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So, for concerned eaters, Consumer Reports recommends buying sustainably raised, grass-fed beef, which is both more humane and less likely to be filled with either shit or drugs. And, if you’re a carnivore who’s still squicked out by the thought of all those hundreds of cows in your poop burger, well, you may want to just order the steak.