Each can be checked in a few minutes against the official text cited.
Buenos Aires or Bogotá: three months apart for the same dog
To enter the European Union, a dog from Argentina, Chile or Mexico needs no rabies antibody titration test: these countries are listed in the annexes of Regulation (EU) 2026/636. From Brazil, Colombia, Peru, Ecuador, Bolivia, Paraguay, Uruguay or Panama, one is required, which adds about three months of preparation.
New EU certificate from 1 October 2026: the date extends nothing
A health certificate signed up to 30 September 2026 may still follow the old model; from 1 October, the new one applies. Either way, it is valid for only 10 days between issue and entry into the EU. EU pet passports issued on the old model, by contrast, remain valid until 1 January 2028.