Reflection paper on the authorisation of veterinary medicinal products containing (potential) persistent, bioaccumulative and toxic (PBT) or very persistent and very bioaccumulative (vPvB) substances(关于含有（潜在）持久性、生物累积性和毒性（PBT）或非常持久性和非常生物累积性（vPvB）物质的兽药产品授权的思考文件)