Prior to the introduction of the pet passport, when an animal entered a foreign country, it might be quarantined for an extended period of time to ensure that it was not infected with harmful diseases. If a quarantined animal did display signs of infection, he or she might be destroyed or deported, depending on the policy of the host nation. In addition to being stressful for the animal and expensive for the owner, quarantine could be a major headache for administrators, many of whom welcomed the pet passport.
A typical pet passport includes basic information about the animal, including a picture, description, and information about the owner. It also contains information about the animal's microchip or identification tattoo; such identifications are required for pets who want to apply for pet passports. Pet passports also include proof of rabies vaccination and serology tests to confirm the presence of rabies antibodies, and they include signed veterinary certificates.
The pet passport system is not standardized, and you should be careful when obtaining a pet passport. As a general rule, it's a good idea to approach the embassy or department of state of the country you wish to travel to in order to get information about pet passports and travel requirements. Make sure that you use an approved veterinarian for the examinations and certificates, as not all veterinarians are approved to sign off on pet passports, and you do not want to be detained at the border due to a petty technicality!