Which statement about the cascade is true?

• A. It allows use of medicines not licensed for that species/condition when licensed options are not available
• B. It prohibits any non-licensed use
• C. It only applies to medicines for humans
• D. It requires a dietary supplement instead of medicines

Answer: (A)

The cascade allows using medicines not licensed for that species or condition when licensed options aren’t available. This safeguards animal welfare by ensuring treatment can still be given even if a perfect, licensed product doesn’t exist. In practice, a veterinarian follows a stepwise path: first seek a product licensed for the same species and condition, then consider medicines licensed for another species or condition if appropriate, and only then move to human medicines or other non-licensed options with careful justification, proper dosing, and adherence to withdrawal periods and record-keeping. It's not a blanket permission or limited to humans, and it doesn't require a dietary supplement instead of a medicine.