Veterinary medicinal products (VMPs) are used to treat, prevent or diagnose diseases in animals. Pharmaceutical substances authorised to be used in these VMPs within the EU are indicated in Regulation (EU) 37/2010. However, outside the EU, regulations differ and the list of substances authorised thus deviates from the EU legislation. When animals are treated with substances that are unauthorised in the EU, these substances may end up in animal by-products that are imported into the EU and used in animal feed. The aim of this research was to make an inventory of substances that are authorised for use in food producing species outside the EU but not within the EU. Focus was on relevant countries with significant export towards the Netherlands. The research gives a summary of relevant EU regulation in order to gain insight in the possible products entailing the group of animal by-products as well as the authorised presence of pharmaceutical substances in these products. Then, the most relevant animal by-products specified by their CN code (Combined Nomenclature for classifying goods as specified in Customs Regulation (EEC) 2658/87) were identified and used to obtain the import volumes for non-EU countries. Subsequently, RASFF data and aquaculture production volumes were used to select the most relevant non-EU countries for import of animal by-products in the Netherlands. This resulted in 20 countries from a wide geographic origin. For these countries, the regulation with respect to Maximum Residue Limits (MRLs) was evaluated assuming this is an indication of the availability of an authorised VMP. The evaluation resulted in a list of 104 substances for which MRLs have been established in one or more of the included countries, but that are not authorised in the EU. Most of these substances were antiparasitics or antimicrobials. The top 5 countries with considerable number of authorised substances not included in EU legislation are Indonesia (44 substances), China (28 substances), India (28 substances), US (27 substances), and Australia (23 substances). China, in this respect, is the most relevant country as most animal by-products are imported from China (69 kton/y) followed by Brazil (47 kton/y), the US (3 kton/y), New Zealand (1 kton/y) and Indonesia (0.8 kton/y). For some countries, i.e. Chile, Turkey, Vietnam, Ukraine and Uruguay no substances were found that are authorised in these countries but not within the EU. Apparently, these countries have harmonized their legislation with the EU. Further research is needed to establish whether the identified substances are actually used in the country of origin and whether residues occur in animal by-products entering the EU feed market. It is recommended to extend the national monitoring program for feed with substances for which there is an indication of use in animal production relevant for animal by-products.