I heard there was a change in the yearly booster requirement, that it's no longer deemed necessary to have a booster every year, that the original vaccination lasts for up to three years and more, that vets are not alerting the public to this change because it cuts into their business but the American Veterinary Medical Association sent out findings that this was the ruling now and vets were to tell their clients about this change. Some are. Some aren't. Does anyone have a link that can substantiate this?(thanks)