Marcus qualified from the Royal Veterinary College in 1994 and spent a period in mixed practice before undertaking an internship at the Animal Health Trust Equine Clinical Unit. A second internship at The Royal Veterinary College in London was followed by a move to Rossdale & Partners (Newmarket) in 1996, as an assistant dealing with horses in training. In 2004 he moved to the Practice’s Diagnostic Centre to work on referral cases full-time and he now sees orthopaedic cases from a wide variety of disciplines, occasionally escaping to attend Thoroughbred sales. His main area of interest lies in diagnostic imaging, particularly ultrasonography. He has authored and contributed to a number of articles in peer-reviewed journals and written chapters for several books on scintigraphy, ultrasonography, back problems and lameness. He was awarded the BEVA Richard Hartley Clinical Prize, with Rob Pilsworth, in 2000 and has regularly delivered lectures at BEVA Congress and elsewhere over the last few years.