John is a veterinary surgeon and partner at Sercombe Veterinary Surgeons. He qualified from The Royal School of Veterinary Studies in Edinburgh in 1971 as a Bachelor of Veterinary Medicine and Surgery (BVM&S) and was simultaneously admitted as a Member of the Royal College of Veterinary Surgeons (MRCVS). After graduating, John worked in practices in UK until January 1976, when he returned to Nairobi and worked there for a couple of years before he founded Sercombe Veterinary Surgeons together with his wife, Patsy. John is licensed to practice as a veterinary surgeon by the Kenya Veterinary Board (KVB) and is a member of the Kenya Veterinary association (KVA) and the Kenya Small and Companion Animal Association (KESCAVA).

In addition to general practice, John loves horse racing and has been involved with the Jockey Club at Ngong Racecourse since the late ‘70s in a number of capacities: veterinary officer, starter of the races and Clerk of the Course. Today he is a member of the club’s Board of Directors and the Executive Committee.