A veterinarian treats a patient who cannot consent, bills a client who is not the patient, and practices on an animal the law usually classifies as property. Every peculiarity in this field follows from that arrangement. This article explains the veterinarian-client-patient relationship, why it is the gateway to prescribing rather than a formality, and what happens when it does not exist. It explains extralabel drug use — the doctrine that makes most veterinary pharmacology lawful — and the conditions attached to it. It covers controlled substance obligations that apply to veterinarians identically to physicians, and the diversion patterns that generate cases. It covers malpractice: why damages are usually limited to the animal's market value, the doctrines under which that limit is escaping, and what the informed consent conversation must cover when the decision is financial as much as clinical. It covers euthanasia, abandonment, ownership disputes, technician scope, corporate ownership, and the board complaint. It closes with what a practice should document.