A California start-up called Clear Food has done the Thing That Should Not Be Done: analyzed what's actually in a bunch of different hot dogs. They took samples from 345 different hot dogs and sausages, and as you might be able to guess, the results weren't that "these hot dogs were made from grade A organic meat that's raised in conditions so great, the animals have higher thread-count sheets than you." In fact, 15% of the samples had "evidence of meats not on the labels." This includes pork products in sausages that are supposed to be chicken or beef, as well as animal products in dogs that were supposed to be vegetarian. And this on the same day that the World Health Organization tells us bacon causes cancer.
But perhaps even more disturbing than that is this: 2% of the samples tested positive for human DNA. You might be thinking that a secret evil hot dog lab has developed the perfect hot dog animal: a cross-breed that's 98% cow and 2% human, so it probably looks like a cow, but with a gorgeous head of human hair.
That's not the case, though, because 2/3 of the samples that tested positive for human DNA were "vegetarian." There were actually a lot of problems with the vegetarian dogs — the study also found that many of them exaggerate their amount of protein, 10% of the vegetarian items actually contained meat, and "vegetarian items accounted for 67% of the hygienic issues found in the report." If you're curious, human DNA is considered a contaminant in the report rather than a meat, so at least we're not cannibals.
If you want to know if your favorite hot dog brand creates a "hot dog with integrity," Clear Food has a list of the best-scoring brands in its report.