For some countries it is necessary that the papers / health of the dogs must be legalized before they can return to their own country. This is done in the Netherlands by the government agency NVWA. More information can be found on the page “Repatriating dogs and legalization”.
Please note that this repatriation legalization is only necessary for a few countries such as Australia, Japan, China, Indonesia, South Africa etc. etc.
This is not for the deworming and stamps such as needed for Great Britain and Scandinavia. This is a free service when you bring your own medication.