The Food and Drug Administration has become aware of recent incidents involving the misuse of doramectin to treat dairy cattle. Doramectin is not approved for use in female dairy cattle 20 months of age or older. If a lactating cow is exposed to doramectin, milk from the cow may have detectable residues of the drug for as long as 60 days. Any detectable amount of doramectin in milk is considered illegal.
"Food animal producers should remember to read veterinary drug labels carefully and follow label directions to help avoid causing illegal residues in their products," says Dr. Stephen Sundlof, director of FDA's Center for Veterinary Medicine.
Doramectin (NADA 141-095) is approved for topical use to treat and control various worms (roundworms, lungworms, and eyeworms), grubs, lice, horn flies, and mange mites. It is also approved to control infections and to protect from reinfection with Cooperia oncophora and Dictyocaulus viviparus for 21 days; Ostertagia ostertagi, C punctata, and Oesophagostomum radiatum for 28 days; and Haemonchus placei for 35 days after treatment.
Under the Animal Medicinal Drug Use Clarification Act of 1994 amendments to the Federal Food, Drug, and Cosmetic Act, licensed veterinarians are permitted to prescribe extralabel uses of approved animal drugs and human drugs in animals under certain conditions specified in Title 21, Code of Federal Regulations, Part 530, http://origin.www.fda.gov/cvm/index/amducca/530.pdf. Nonveterinarians, however, are not permitted to use drugs in an extralabel manner.
As mentioned in the compliance policy guide "Proper Drug Use and Residue Avoidance by Nonveterinarians," www.fda.gov/ora/compliance_ref/cpg/cpgvet/cpg615-200.html, extralabel use of drugs by nonveterinarians in food-producing animals is a significant public health concern and a contributing factor in illegal residues in edible animal tissue. Such use of drugs is illegal under the Federal Food, Drug, and Cosmetic Act.