There is some information here:
Bringing Pet to US - Bring a Pet Dog Cat (dogs cats) Import Pets, US Customs Requirements Inspections DogsDomestic dogs must be free of evidence of diseases communicable to humans when examined at the port of entry. If the animal is not in apparent good health, further examination by a licensed veterinarian may be required at the owner's expense. Collies, shepherds, and other dogs that are imported from any part of the world except Canada, Mexico, and regions of Central America and the West Indies and that are to be used in the handling of livestock must be inspected and quarantined at the port of entry for a sufficient time to determine their freedom from tapeworm.
Dogs must be vaccinated against rabies at least 30 days before entering the United States. This requirement does not apply, however, to puppies less than three months of age or to dogs originating or located for at least six months in areas designated by the
U.S. Public Health Service as being rabies-free.
The following procedures pertain to dogs arriving from areas that are not free of rabies:
A valid rabies vaccination certificate should accompany the animal. This certificate should be in English or be accompanied by a translation. It should identify the animal, the dates of vaccination and expiration, and be signed by a licensed veterinarian. If no expiration date is specified, the certificate is acceptable if the date of vaccination is no more than 12 months before the date of arrival. Some certificates say the vaccine is good for three years. Dogs should not get re-vaccinated if they are within the dates of the certificate.
Dogs not accompanied by proof of rabies vaccination, including those that are too young to be vaccinated (less than 3 months of age), may be admitted if the importer completes a
confinement agreement and confines the animal until it is considered adequately vaccinated against rabies (the vaccine is not considered effective until 30 days after the date of vaccination).
If the vaccination was performed less than 30 days before arrival, the animal may be admitted but must be confined at a place of the owner's choosing until at least 30 days have passed since the vaccination.
Young puppies must be confined at a place of the owner's choosing until they are three months old, then they must be vaccinated. They must remain in confinement for 30 days.
Dogs that arrive in Hawaii or Guam, both of which are free of rabies, are subject to the state's or territory's quarantine requirements, in addition to whatever other Public Health Service requirements, above, apply.
Special Circumstances
Dogs imported from countries or regions where “screwworm” is known to exist may be imported if the dog is accompanied by a certificate signed by a full-time salaried veterinary official of the region of origin stating that the dog has been inspected for screwworm within 5 days prior to shipment to the United States. The certificate must state that the dog is either free from screwworm, or was found to be infested with screwworm and held in quarantine and treated until free from screwworm prior to leaving the region.
Owners of dogs imported from countries or regions affected with Foot-and-Mouth Disease (FMD) are advised to take the following precautions to prevent the introduction of FMD from pets entering the United States:
The feet, fur, and bedding of the pets should be free of any excessive dirt or mud.
The pet's bedding should be free of any straw or hay, or other natural bedding.
The pet should be bathed as soon as it reaches its final destination.
The pet should be kept separate and apart from all livestock for at least 5 days after entry into the United States.
For further information or questions concerning import applications, contact the U.S. Department of Agriculture's (USDA) Animal and Plant Health Inspection Service (
APHIS) at the numbers and locations at the
bottom of this page.
And further down the page is this:
HELP!
All regulations cannot be covered in detail, and regulations are subject to change. If you plan to enter the U.S. with a pet, contact your local U.S. Customs and Border Protection office,
your nearest U.S. Consulate or Embassy, or the specific agency mentioned. Their addresses and websites are:
APHIS
U.S. Department of Agriculture
Animal and Plant Health Inspection Service
National Center for Import and Export
Technical Trade Services, Animal Products Staff
4700 River Road, Unit 40
Riverdale, MD 20737-1231
Tel. (301)734-3277, 301-734-8364
Fax (301)734-8226, 301-734-6402
USDA port veterinarians
Permit application (Form VS17-129) for birds entering via an airport
U.S. Public Health Service
Centers for Disease Control and Prevention
Division of Global Migration and Quarantine (E-03)
Atlanta, GA 30333
Tel. (404)639-8107
Confinement agreement for non-vaccinated dogs