To import dogs and cats into Australia you must comply with the import conditions from the Department of Agriculture. You can check the latest requirements here. Thailand is a non-approved country, so the following steps must be followed.
You are only allowed to import a dog or cat from a non-approved country indirectly through one of the Department of Agriculture’s approved Category 3 countries. This is a two step process, you must first contact the quarantine service in the approved Category 3 country to ensure that cats and dogs are eligible for entry and your pet meets all of the pre and post-entry quarantine requirements of the approved Category 3 country.
Your pet must be prepared, i.e. examined, tested and vaccinated in an approved Category 3 country, and be exported from the same country. You pet may return to the non-approved country after the initial rabies vaccination and testing and return to the approved Category 3 country while final preparations are being done for export. You must have the appropriate paperwork signed by a veterinary authority in the Category 3 country, and your pets must meet all of the Department of Agriculture conditions that apply to the specific Category 3 country before being eligible for import into Australia.
All examinations, treatments, vaccinations, blood samples and blood testing that are required by the Department of Agriculture must be conducted by a veterinarian who is approved by the government of the approved Category 3 country. The Department of Agriculture will not recognize any examinations, treatments, vaccinations, blood samples, blood testing or certification completed in a non approved country.
As an example
• Your pet is currently in Country A
• Country A is not an approved country
• Country B is an approved Category 3 country
• the Country B government allows cats/dogs to be imported from Country A to Country B
• Your pet receives rabies vaccinations and testing in Country B and certification is provided by the Country B by a veterinary authority
• Your pet returns to Country A
• About 5 months later your pet returns to Country B until the time of export to have final preparations undertaken by an approved veterinarian
• Your pet spends about a minimum of 45 days in Country B for the preparations to be completed
• The final vet check is performed in Country B, 5 days before export to Australia
• Certification of the permit conditions is provided by the Country B Official Government Veterinarian
• Your pet is exported from Country B to Australia.
You can read through more information on the import conditions relevant to specific Department of Agriculture approved countries on the website here.