In case of loss of documents, immediately apply to the nearest police station. If you have lost your passport, also contact your consulate, because if the passport is not found, you will need to obtain a temporary permit to enter your country. To speed up the procedure for confirming identity at the consulate, it is advisable to provide originals and copies of your documents there.
In case of missing things and pets, you can file a report with the police and use the websites: www.cpasperdu.com , www.pawmaw.com , www.i-cad.fr/articles/perte-animal-demarches, www.trouve-perdu.com .