While Mr. Hill's editorial letter of last week's statement that in North Carolina a pet (dog or cats only) can receive a one- or three-year rabies certificate was technically correct, he was incorrect in stating that the vaccine used for the certificates is the same. For a veterinarian to legally provide a three-year certificate, they must use a rabies vaccine that is licensed and has been laboratory tested and certified to have a three-year duration of immunity. These three-year vaccines cost more per dose than a one-year vaccine. Many local veterinarians offer both one- and three-year vaccinations at their clinics. The use of which vaccine is decided over age of pet, lifestyle, species, and the financial constraints placed on us by the owner.