The use or storage on dairy farms of any withdrawn nitrofuran or the use of sprays, powders, solutions, ointments, salves, and creams labeled for use in horses, dogs, and cats violates item 16r. The following list of drugs are applied as topicals for their systemic effect against internal parasites or cattle grubs. They are not topical antiseptics or wound dressings and they are not labeled for use in lactating dairy cattle and therefore they are not exempt under the Item 16r footnote. Because of their potential to cause residues in milk, the use of these drugs on lactating dairy cattle or their storage with the lactating cattle drugs is a violation of item 16r. There are no FDA approved uses for DMSO in food-producing animals.
Approvals do exist for uses in horses and dogs.
Industrial grade DMSO is widely available for various non-medical uses such as paint remover and other solvent uses. DMSO is often found stored on dairy farms or mixed with other drugs intended for use in dairy animals. Such use may lead to an increased chance of drug residues, off odor and off flavor milk. FDA considers the use of DMSO for any veterinary purposes other than approved uses in dogs and horses to be illegal. DMSO is an unapproved new animal drug which is unsafe to use in food-producing animals.