Children do not require any additional documents or measures to enter a country that an adult would not require.
All dogs and cats will require the following:
A rabies vaccination at least 30 days before, but not more than 12 months, to entry
A Veterinary Certificate for Argentina signed and completed by a USDA or CFIA accredited veterinarian
A copy of the rabies certificate
A health certificate issued within 10 days of travel
It should be noted that the airline must notify the station manager at the point of entry and will be examined at the point of entry in Argentina. A $25 customs fee will apply.
Although it’s not enforced, it’s recommended that you microchip your cat or dog prior to travelling.