The standardization of the injection sites of animal species is related to different species and several fields of interest.After decades of market experience, migration of the transponder is still a problem in most animal species being identified by injectable transponders. Migration is related to several factors. The major issues are the injection site and the application of the injectable transponder but the correct injection site can be dictated by the dimensions (length and diameter) of the injectable transponder. In dogs and cats, this is not a big issue as the transponders used are the smallest readily available. There are several publications which precisely describe the application of injectable transponders anatomically but there is a demand from the community to have a comprehensive overview of all aspects related to the application and use of injectable transponders for different animal species.