This particular comment about the Danish experience by Dr Scott Hurd has received wide coverage in the USA and abroad as part of the furore following tests suggesting that one quarter of American meat carries antibiotic resistant disease.
Let’s take the definitions, figures and facts un-argued, and just deal with the interpretation.
New study adds to concerns about animal-to-human resistance to antibiotics
Evidence suggests that routine use of antibiotics on animal farms is leading to antibiotic resistance in humans. A look at what's known and what's being done.
But Dr. Scott Hurd, a trained veterinarian and researcher at Iowa State University in Ames, says industry numbers show that only 13% of antibiotics used in food animal farming are for growth promotion and adds that preventive use is necessary in certain situations. "It's always based on previous experience, when you know the animals are going to get sick," he says. He notes that in Denmark, the amount of antibiotics used for treatment has doubled, indicating that a lot more animals are getting sick.
Hurd adds that changing practice in the name of public health would be counterproductive. "We lose a lot of our tools to keep animals healthy," he says. "Even marginally ill animals are more likely to be contaminated with Salmonella and Campylobacter, so you have the potential to decrease public health."…
It was ironic that this should appear in California.
If you are dealing with future events, by their very nature you can’t be sure of outcomes. It is logical and sensible to assume that some “preventative” use of antibiotics was actually unnecessary.
So the condition “…when you know the animals are going to get sick," is obviously not always applicable and antibiotics are sometimes used when not needed.
What the unnecessary proportion may be is a matter for conjecture, but since the benefits of antibiotics are additional growth in healthy animals, it is reasonable to assume that it is high. Judgement in cases of doubt will naturally veer towards what is, from a profit and individual pig point of view, beneficial.
Nobody doubts that the use of antibiotics for growth promotion prevented some illness anyway, so it is entirely logical to assume that the ban on growth promotion would lead to a rise in therapeutic use. The methods of administering medicines to a herd of pigs does tend to make a blunderbuss approach inevitable anyway: the healthy get treated with the ailing.