The following is copied from a 2004 Guatemala government info document.
It seems that when entering in your own vehicle by land, that most travellers don't have anything more than a rabies certificate. Of course, you're taking a chance of being denied admission.
BRINGING YOUR PET TO GUATEMALA
• You must first take your pet to a U.S. registered veterinarian for a
health certificate stating that the pet has been examined, shows no
evidence of communicable disease, and has been vaccinated for
rabies, distemper, hepatitis, leptospirosis, and parvovirus. The
certificate must be executed within 30 days prior to the animal's
entry into Guatemala. Not all U.S.-based veterinarians can perform
certification, so be sure to check first that your veterinarian can
provide or recommend someone for this service.
• Then take or mail the health certificate to the nearest office of
the Department of Agriculture in the United States that approves
health certificates for pets.
• After the certificate has been approved by the Department of
Agriculture, you will need to have it authenticated by the
Guatemalan Embassy or a Guatemalan Consulate in the United States.
Frank in Toronto
formerly:
2 Westfalia campers (in Europe)
2 VW/Winnebago Eurovan campers
2004 Rialta HD :
Now: 2001 Hymer B654 in Europe: the "Jefferson Campervan"
The Jefferson Campervan Travel Pages