The AVMA's Principles of Veterinary Medical Ethics is important reading for any veterinarian.
An excerpt from these principles follows:
"Exemplary professional conduct upholds the dignity of the veterinary profession. All veterinarians are expected to adhere to a progressive code of ethical conduct known as the Principles of Veterinary Medical Ethics (the Principles). The basis of the Principles is the Golden Rule. Veterinarians should accept this rule as a guide to their general conduct, and abide by the Principles. They should conduct their professional and personal affairs in an ethical manner. Professional veterinary associations should adopt the Principles or a similar code as a guide for their activities."