Moving my horse(s) from Brighton, Colorado to Belize !

I imported our two dogs. I don't know about horses, but here is the website from the government department that looks after importing of animals (Belize Agricultural Health Authority). You will need to get a permit to import the horse, as well as pay a fee for the permit, and then another fee when they examine the horse.

Government WebSite: http://www.baha.bz/animal_health.html

I expect that you will be driving down through Mexico. Therefore you will need to have all of the permits to have the horse in Mexico as well. I do not know the websites for Mexico.

Colorado is a similar climate to Alberta Canada. There are not a lot of parasites in Alberta. When you come down here there are many more. Educate yourself on these, and be prepared. I would recommend that you make contact with a vet once you get here to understand this.