The Food and Drug Administration's Center for Veterinary Medicine reminds veterinarians that extralabel use of sulfonamides in lactating dairy cattle is prohibited.
The CVM has received information indicating that sulfonamides, some in combination with trimethoprim, are being prescribed for use in treating conditions in lactating dairy cattle for which they are not approved. Unapproved use of sulfonamides is one of the most frequent causes of violative residues in food-producing animals.
The prohibition against extralabel use of sulfonamides in lactating dairy cattle is based on a finding by the CVM that the extralabel use of these drugs presents a risk to the public health.
The following drugs—both animal and human formulations, families of drugs, and substances are prohibited for extralabel uses in all food-producing animals: chloramphenicol; clenbuterol; diethylstilbestrol; dimetridazole; furazolidone, nitrofurazone, other nitrofurans; fluoroquinolones; glycopeptide; ipronidazole; other nitroimidazoles; phenylbutazone animal and human drugs in female dairy cattle 20 months of age or older; and sulfonamide drugs in lactating dairy cattle, with the exception of approved use of sulfadimethoxine, sulfabromomethazine, and sulfaethoxypyridazine.
Currently, sulfadimethoxine is the only marketed sulfonamide with approved formulations for lactating dairy cattle. Products on the list of prohibited drugs may be used only according to the approved indications in their labeling. Some formulations are not specifically approved for lactating dairy cattle. Some of the prohibited drugs are approved for one class of food animal but not others. Veterinarians should read drug labels closely.
Veterinarians with questions about the extralabel use of drugs may contact FDA-CVM Division of Compliance, 7519 Standish Place, HFV-230, Rockville, MD 20855; phone, (240) 276-9200.