Maybe the public response had something to do with this reversal? And if you had to pick a class, I think cephalosporins are a good group:

Cephalosporins are commonly used in humans to treat pneumonia as well as to treat skin and soft tissue infections. In addition, they are used in the treatment of pelvic inflammatory disease, diabetic foot infections, and urinary tract infections. If cephalosporins are not effective in treating these diseases, doctors may have to use drugs that are not as effective or that have greater side effects.

In addition, some of the new truly terrifying antibiotic resistance genes, such as NDM-1 and the KPCs, which confer resistance to all penicillin derivatives, also confer resistance to cephalosporins. That means, if these genes get into the agricultural system, subtherapeutic use of cephalosporins would give these strains an edge and potentially help them increase in frequency outside of the hospital.

I’ll also note that cefepime and cefquinone are part of this group. This ruling overturns some very stupid policy enacted during the Bush administration.

With this new ruling, the FDA also hasn’t provided much wiggle room either:

In its order, FDA is prohibiting what are called “extralabel” or unapproved uses of cephalosporins in cattle, swine, chickens and turkeys, the so-called major species of food-producing animals. Specifically, the prohibited uses include:

•using cephalosporin drugs at unapproved dose levels, frequencies, durations, or routes of administration;
•using cephalosporin drugs in cattle, swine, chickens or turkeys that are not approved for use in that species (e.g., cephalosporin drugs intended for humans or companion animals);
•using cephalosporin drugs for disease prevention.

In 2008, FDA issued and then revoked an order that prohibited extralabel uses of cephalosporins in food-producing animals with no exceptions. Today’s announcement responds to public comment and includes the following exceptions, which protect public health while considering animal health needs:

•The order does not limit the use of cephapirin, an older cephalosporin drug that is not believed by FDA to contribute significantly to antimicrobial resistance.
•Veterinarians will still be able to use or prescribe cephalosporins for limited extra-label use in cattle, swine, chickens or turkeys as long as they follow the dose, frequency, duration, and route of administration that is on the label.
•Veterinarians may also use or prescribe cephalosporins for extralabel uses in minor species of food-producing animals such as ducks or rabbits.

This is a solid set of guidelines, although I don’t like the duck and rabbit loophole. Regardless, I hope this ruling will stand.

Between this and the recent recess appointments, maybe the Obama administration is starting to realize that they have the capacity to govern administratively.