Increased scrutiny of antibiotic residues in cull dairy cows is forcing many veterinarians to re-think their participation in extra-label drug use authorization.
About 10% of the dairy veterinarians attending this week’s Dairy Wellness Summit here in Phoenix say they have discontinued virtually all Extra Label Drug Use (ELDU) with their clients. One Idaho vet says his clinic no longer even sells penicillin to clients. That’s because labeled doses are generally considered ineffective, but higher, effective does are ELDU.
Licensed veterinarians do have the authority to prescribe drugs that do not have a label claim for a particular disease if the drugs labeled for such use are ineffective. But that’s the catch: It is very difficult to prove that labeled drugs are not effective on a particular dairy.
The ELDU issue has come to the forefront now that the Food and Drug Administration (FDA) has begun to publicly identify farms that have antibiotic residues in cull cows. Many of these residues come from ELDU. FDA plans to start conducting antibiotic tests of the milk from these same farms later this year.
The problem with ELDU is meat withdrawal times become a dicey proposition because there is little or no data on how fast these drugs clear tissue. Vets are required to contact the Food Animal Residue Avoidance and Depletion
Program to get a withdrawal period. “Often times, these cows will become ‘pets’” because the milk withdrawal times can stretch to 40 days or more, and meat withhold can stretch to 60 days and longer, says Gary Neubauer, a veterinarian with Pfizer Animal Health.
In addition, FDA has announced that if the ELDU antibiotic does not have a lactation label claim and is used in a lactating animal, it must have zero residue of that drug in the meat at the time of slaughter. Consequently, with today’s highly sensitive tests, any residue detected is a violation.