New Animal Drugs for Use in Animal Feed; Category Definitions

The Food and Drug Administration (FDA, the Agency, we) is amending the animal drug regulations by revising the definitions of the two categories of new animal drugs used in medicated feeds to base category assignment only on approved uses in major animal species. This revision will preserve the availability of medicated feeds intended for therapeutic use in minor animal species and prevent a significant disincentive for future development of additional minor species therapies.