In which regulation would you find guidelines pertaining to drugs intended for animal use?

The guidelines pertaining to drugs intended for animal use can be found in Title 21 of the Code of Federal Regulations, specifically in part 500s. This part provides the regulatory framework for the approval and oversight of animal drugs and outlines the requirements that must be met for the safety and effectiveness of these products before they can be marketed. This regulation is essential for ensuring that animal drugs are appropriately evaluated to protect animal health and, by extension, human health, as diseases that affect animals can sometimes impact the food supply or human populations.

In contrast, the other options refer to different aspects of the regulatory framework. For example, parts 600s generally deal with biological products for human use, 814 relates to premarket approval for medical devices, and 807 includes regulations regarding the registration and listing of medical devices intended for human use. Thus, the focus of the correct answer is distinctly on animal drugs, which makes it the appropriate choice for this question.