Haw. Rev. Stat. § 143-2: License or microchip required.

It shall be unlawful for any person to own or harbor a:

(1) Dog unless the dog is licensed and has been implanted with a microchip identification as provided by this chapter; provided that the counties may, by ordinance, dispense with or modify the licensing requirements of this chapter; provided further that this chapter shall not apply to dogs under the age of three months or dogs brought into the State exclusively for the purpose of entering them in a dog show or exhibition and not allowed to run at large; or

(2) Cat unless the cat has been implanted with a microchip identification as provided by this chapter; provided that this chapter shall not apply to cats under the age of three months or cats brought into the State exclusively for the purpose of entering them in a cat show or exhibition and not allowed to run at large.