The Food and Drug Administration's (FDA's) new rules tightening the use of cephalosporins in food animals may end up affecting how cattle veterinarians, cow-calf producers and cattle feeders use these drugs to treat illness in their animals, says Russell Daly, SDSU Extension veterinarian.
Cephalosporins are a family of drugs that are used in both people and animals. The cephalosporins most beef producers are familiar with are the injectable ceftiofur products Naxcel (and its generic equivalents), Excede, and Excenel. Cephapirin is a cephalosporin used in mastitis preparations for dairy cattle, but it has been exempted from the new rules.
Because of cephalosporins' close relation to drugs used in people, the FDA has sought to clamp down on the uses of these drugs in animals, Daly explains. In 2008, the FDA proposed rules that would mean these drugs could only be used strictly according to their labels, even by veterinarians. The current proposed rules are less restrictive to veterinarians and producers than those proposed back then.
One major effect of the new rules would be to end the use of cephalosporin drugs that are not approved for use in a certain species, Daly says. For example, veterinarians by law have been able to use human-labeled antibiotics to treat sick animals when no labeled food animal drug is available. This has been more of an issue in swine medicine, but a veterinarian who once was able to treat a calf with a cephalosporin drug approved for dogs, for example, would no longer be able to do this.
Extra-label use of the approved injectable drugs is still allowable (under a valid Veterinary Client Patient Relationship (VCPR), as always), but with certain limits, Daly says. These drugs may still be used to treat conditions in calves, cows, or bulls that are not listed on the label. For example, under a VCPR, a veterinarian or producer could still use these drugs to treat a salmonella infection in a calf, despite that not being a listed use on the label.
What will not be allowed anymore, however, is to use a higher or more frequent dose, or to give the drug by a route of administration that is not spelled out on the label (like IV injection of a preparation labeled for intramuscular use). In short, veterinarians and producers with a VCPR can still use these drugs for conditions not listed on the label, but the dose, route, and frequency listed on the label need to be adhered to,Daly says.. These injectable products, as before, are only available through a prescription from a veterinarian.
In addition, the new rules prohibit use of cephalosporin drugs to prevent disease.
"The question arises about the use of these drugs for metaphylaxis. Metaphylaxis refers to the practice of treating a group of high-risk cattle upon arrival at a feedlot with full doses of an injectable antibiotic as a means of treating animals already showing signs of illness, along with those who are subclinically affected. Whether this practice will still be allowable with cephalosporin drugs is still the subject of some discussion. In general, since these products are labeled for 'control', it's possible that metaphylactic use for bovine respiratory disease will still be allowable. Cattle producers should, however, discuss the ramifications of these potential new regulations with their veterinarians," Daly says.