It is. The only required membership is a license from the jurisdiction in which the veterinarian is practicing. Many vets are members of their state veterinary medical association, the AVMA and/or the AAEP or the state’s Equine Practitioner’s association and those organizations have governing principles and suggested or model rules, but each state’s disciplinary rules are different.
IIRC, and I don’t have my rule book handy, but I do have a pretty good grasp of all the rules
in Florida, a licensed vet is a mandatory reporter of other veterinarians infractions, and that is particularly clear when it is an impaired practitioner. There is also some situations where a licensee can report animal cruelty or abuse or cooperate with an investigation without being in violation of the requirement that the animal’s medical records are confidential. Additionally, section 828.12(4), Florida Statues provides immunity in criminal and civil actions if a vet does participate in an investigation or makes such a report.
However, Florida does not have an ethical obligation, or perhaps I should say, it is not a specific violation of the disciplinary guidelines to fail to report animal abuse or cruelty. It appears, based on Flightcheck’s comment above, that North Carolina is similar in that their licensees are also not mandatory reporters.