Human drugs or nutritional supplements available without a prescription are known as over-the-counter (OTC) medications. Exposures to OTC drugs in pets can be accidental or intentional. A valid client-patient-veterinarian relationship must exist for veterinarians to recommend extra-label use of these drugs to their clients. Most are not approved for veterinary use by the FDA, and safety of most OTC drugs has not been determined in animals. Veterinarians should understand the potential risks of using OTC medications and communicate these risks to their clients.