FDA announcement here:

http://www.fda.gov/AnimalVeterinary/NewsEvents/CVMUpdates/ucm054434.htm

To expand a bit: ‘Labeled use’ is the use printed on the factory label. When the ivormectin says “for use in cattle for the treatment of (lists species of parasites) at a IM dose of X ml per 10 lbs, not for use in lactating dairy cattle, stop use X days prior to slaughter” – then the drug is labeled for cattle at that dose, by that administration route (injected IM) for that disease (parasites) and with that withdrawal period.

“Extralabel use” is using drugs in a way not labeled. It is not legal for laymen to use a drugs in a MEAT animal unless that drug is labeled for that species and use (see: “do not use in lactating dairy cattle”). In some cases, giving a drug by ingestion instead of injection, or vice versa, significantly increases the length of time the drug is in the body of the animal.

All the previously legal extra-label uses that are now prohibited by this new rule were under the direction of a vet, as it was not legal to use this drug extralabel without vet direction.

It does not matter if the drug was bought with a prescription or OTC – it matters if the drug is labeled for that animal, so that the directions can be clearly understood and the proper withdrawal times followed.

(MEAT here referes to meat, egg, and milk.)

Vets can prescribe drugs in ‘extra label’ manners under specific circumstances to meat animals, and only if they give a new withdrawal time for that use.

For some drugs, the FDA has completely prohibited their use in food animals, even under prescription of a vet. Some of these drugs are still widely used in companion animals, to include horses. For other drugs, the FDA permits labeled use, but prohibits use, even under the direction of a vet, in extralabel ways. So far, this has been done to prevent widespread use of sensitive antibiotics and prevent increase in drug resistant organisms. (This applies to theraflu and the like, which can’t be used in poultry to help fight off avian influenza.)

The link goes into more details on why the rule was put in place.

An exerpt is quoted below:

“FDA’s Center for Veterinary Medicine is issuing an order that prohibits the extralabel use of cephalosporin drugs (not including cephapirin) in cattle, swine, chickens, and turkeys. 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.

The following exceptions to the prohibition apply:

* Extralabel use of approved cephapirin products in food-producing animals;
* Use to treat or control an extralabel disease indication, as long as this use adheres to a labeled dosage regimen (i.e., dose, route, frequency, and duration of administration) approved for that particular species and production class; and
* Extralabel use in food-producing minor species, such as ducks or rabbits.”

 

Another article you can look at.

  1. “The action was taken, the agency said, “to preserve the effectiveness of cephalosporin drugs for treating disease in humans. Prohibiting these uses is intended to reduce the risk of cephalosporin resistance in certain bacterial pathogens. 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.” “