[...] critics say repeated use of antibiotics has made bacteria more resistant to the drugs, resulting in people developing antibiotic-resistant infections. Scientists, doctors and public health officials are unequivocal about the need to stop the spread of antibiotic-resistant superbugs. [...] some farmers and veterinarians say the bill would essentially bar them from using antibiotics to prevent disease outbreaks — a crucial tool in the treatment of large groups of animals. Unlike in human medicine, on a farm it's critical to treat the herd at the first signs of a bacterial infection, said Charles Meyer, a Grants Pass veterinarian and president of the Oregon Veterinary Medical Association. The Centers for Disease Control and Prevention estimates antibiotic-resistant bacteria cause 23,000 human deaths and more than 2 million illnesses each year in the U.S.