Which of the following controlled drugs cannot be dispensed under any circumstances?

Ketamine is classified as a controlled substance in many jurisdictions, including Canada, due to its potential for abuse and its serious side effects. In the context of the College of Veterinarians of Ontario (CVO) regulations, Ketamine falls under the category of controlled drugs that are heavily regulated. This means that it cannot be dispensed under any circumstances unless specific legal procedures are followed.

The other drugs listed, such as Amoxicillin, Cephalexin, and Tramadol, have different classifications and regulations surrounding their dispensing. Amoxicillin and Cephalexin are antibiotics that are not classified as controlled substances, making them widely accessible for prescription and dispensing under normal veterinary practices. On the other hand, Tramadol, while it is subject to some regulations, is not as strictly controlled as Ketamine, and therefore can be dispensed in certain situations when prescribed appropriately.

Understanding the classification of substances and the legal implications of dispensing controlled drugs is crucial for veterinary professionals to ensure compliance with regulations and to prioritize animal and public safety.