A multitude of diseases and parasites might be encountered in a foreign environment. The disease-causing organisms that animals may harbor have the potential to produce serious consequences. For example, in 2003 an outbreak of monkeypox in people in the United States was traced to Gambian giant rats, which carried the virus from Africa. The rats infected prairie dogs intended for the pet market, and the prairie dogs, in turn, infected people.
Depending on the country you are returning from, there may be specific requirements to meet before leaving the country.
When citizens return to the United States, their pets—which may be infected with foreign diseases or parasites—are also presented for re-entry into the country. Dogs, cats, and certain other pets are subject to measures designed to prevent the introduction and spread of parasites and rabies and other zoonotic diseases (diseases that humans can get from infected animals). If an animal is found to have one of these diseases, the case must be reported to the appropriate state authorities, who in turn, will notify the proper federal agencies.
Upon arrival in the US, owners should schedule a physical examination by a veterinarian. This examination may include blood tests. Pets may need to be treated to resolve any infestations that may have occurred while the animal was in transit. There may be additional restrictions if you enter the Unites States through Puerto Rico, Guam, or Hawaii. Before returning through these ports, travelers should contact animal health inspectors for additional information.
The general re-entry requirement is that all dogs and cats imported into the US be visually inspected by US Public Health Service personnel. Only those animals that are free of any evidence of infectious disease may be admitted. Animals showing signs of illness such as emaciation, skin sores, disturbances of the nervous system, jaundice, or diarrhea, must be examined, tested, or treated at the owner’s expense by a licensed veterinarian designated by the agency.
Regardless of their age, dogs may be admitted to the US without restriction if they appear healthy and have been in a rabies-free area for at least the 6 months immediately preceding arrival in the US or since birth. Dogs coming from a high-risk country will need a certificate proving they have been vaccinated for rabies. Dogs coming from a low-risk country or one that is free of rabies, however, do not need a rabies vaccine certificate.
Dogs arriving from countries other than those listed as rabies-free may be admitted to the US if they are 3 months of age or older, free of any evidence of infectious disease, and accompanied by a valid certificate of rabies vaccination. All 3 requirements must be met. Vaccination certificates must identify the dog, be signed by a licensed veterinarian, and specify the expiration date, which must be after the date of arrival. If the expiration date is not indicated on the certificate, the certificate is considered to be valid for only 1 year from the date of issue. Vaccination certificates should also specify the date of vaccination, which must be at least 30 days before the arrival date.
The USDA should be contacted for requirements specific to dogs used for working livestock to prevent importation of Echinococcus species, which are tapeworms associated with the development of hydatid cysts in livestock and humans. Current regulations should always be checked in advance.
The CDC does not regulate importation of horses into the US unless the horse is known to carry a disease transmissible to humans. The USDA requires quarantine of horses for various time periods (3 to 60 days), depending on which country the horse is entering from. The owner or transporter should contact the port veterinarian at one of the USDA Animal Import Centers to reserve space at the quarantine facility.