1981: graduated at the Utrecht University.
1986: specialist internal medicine companion animals.
Until 1989 fellowship in clinical oncology at the Natl Cancer Institute in Amsterdam.
1989-present: staff member in Internal Medicine of the Dept Clin Scie of Comp Animals, where he is currently head of the Medical Oncology.
1993: PhD on non-Hodgkin lymphoma in the dog.

From 2011 he is part-time professor in medical oncology at the university in Liege. He has written more than 130 publications in refereed journals, 16 book chapters, and more than 150 other publications. He has given over 140 invited presentations at international congresses. He is double boarded in the ECVIM-CA in internal medicine and in clinical oncology and was the first president of this ECVIM-CA, and has been president of the EBVS.
In 2016 he received the EBVS Award for outstanding contributions to veterinary specialisation in Europe.
He is Honorary Member of the ECVCP and was awarded the WSAVA Hill’s Excellence in Veterinary Healthcare Award in 2006 and the WSAVA International Award for Scientific Achievement in 2016.