Willie Loeffen graduated in 1992 as a veterinarian in Utrecht. After his graduation, he worked for 10 years as a veterinarian at the Animal Health Service, both in research and as a field veterinarian, supporting local veterinarians. He was specialised in respiratory diseases in swine.
In 2001 he started working at WBVR as a senior researcher and head of the national reference laboratories for classical and Afrikan swine fever, and later-on also Aujeszky's disease. Since the first of January 2017 he is the head of the Statutory Task unit for Transmissible Animal Diseases. This is an independent unit exclusively working for the Dutch government, carrying out the statutory tasks. The unit is fully operational within WBVR. He is also still the head of the previously mentioned reference laboratories.
Key concepts for the Statutory Task unit are independence, quality, transparency, integrity and a high scientific level.