I am not clear what you are asking but to bring an animal to Belize-besides a health certificate and rabies certificate from a vet in the states, you need an import certificate from BAHA-try this link http://www.baha.bz/animal_health.html
Tim has the correct info, the only thing that has changed is the fees just slightly. If possible I highly recommend taking the water taxi to the island. After reaching Belize City and going through BAHA it is quite an ordeal to be putting the animal back in a kennel and flying on the puddle jumper. REALLY a stress on both of you.