Jonas qualified from Copenhagen University in 2001. His initial job was in mixed practice working with cattle and horses.

In 2004 Jonas was employed at Hoejgaard Equine Hospital and he is one of the directors at Hoejgaard today. In 2015 he became a certified ISELP member.

From 2011 to 2016 Jonas was the national team vet for the senior riders in dressage and showjumping, and since 2017 he has often been team vet for the junior and young riders.

Jonas’ main interests are orthopedic problems and pre-purchase examinations. During the past years ultrasonography has been increasingly included as part of the pre-purchase examinations. In 2021 Jonas did 254 pre-purchase examinations, and the majority of these were between professional or semi-professional riders.