No person shall cause or permit any dog owned or kept by him to run at large within the Town of Bar Harbor. A dog while on any premises other than that of its owner or keeper or while on any public way or place shall be under restraint and not at large within the meaning of this article if it is controlled by a leash, cord, or chain or "at heel" beside a competent person and obedient to that person's commands or on or within a vehicle being driven or parked or within the property limits of its owner or keeper. Nothing in this article shall be held to require the leashing or otherwise confining of any dog, except a bitch in heat, while on the premises of its owner or keeper. A leash, cord or chain used to restrain a dog shall not be more than eight feet long.