It's true that cows and chickens get sick occasionally and require antibiotics to get them back on their clucking and mooing ways. Unfortunately, most of the animals being given a near-daily dose of drugs are perfectly healthy, which is where the problem lies. In the U.S. and Canada, antibiotics are routinely given to animals to encourage weight gain, although their use for this purpose has long-since been banned in many other countries [sources: PBS, Charles]. Both countries are currently embroiled in plans to phase out certain antibiotics, although it will probably take several years to achieve the end goal [sources: Munro, FDA].
Why is antibiotic use such a big deal? Well, animals, much like humans, are capable of developing antibiotic-resistant bacteria when they are too frequently given meds. In turn, bacteria can invade the food that these animals produce, like steak, ground beef and chicken breasts. Then, these superbugs can sicken the people that eat them. Since these bugs are antibiotic-resistant, they can be seriously tough to treat [source: CDC]. Vicious cycle, isn't it?
Fortunately, there are ways around this germy issue. Always make sure to handle raw meat carefully and cook completely to destroy bacteria. As an added layer of protection, seek out the USDA Organic/Certified Organic label and/or a Food Alliance certified label to ensure that your side of beef doesn't come with a side of penicillin [source: Eating Well].