Harold Brommer finished in 2005 his PhD thesis entitled 'Towards detection of functional failure of equine articular cartilage: the metacarpophalangeal joint under scrutiny.' With his group ‘Equine Orthopaedics and Surgery’ he is involved into the research lines 'Regenerative Orthopaedics' and 'Veterinary Clinical Research' within the strategic theme 'Life Sciences.' Within the line 'Regenerative Orthopaedics' he focusses on equine joint disease and more specifically on aspects of early degenerative changes of articular cartilage and follow-up of healing after (surgical) repair. He closely collaborates with the research group Biofabrication in Translational Regenerative Medicine of the University Medical Center Utrecht and internationally with the Finnish research group 'Biophysics of Bone and Cartilage' in Kuopio. Within the line 'Veterinary Clinical Research' he supervises research in the field of monitoring and rehabilitation of horses post-operative after colic surgery and innovative treatments of endodontal diseases in the horse. In the field of gait analysis he supervises a project related to the relevance and effect of the thoracic sling posture on forelimb kinematics and kinetics of the horse in exercise. He also collaborates with the farriers of the Faculty of Veterinary Medicine on the development of 3-D printed horseshoes.