Nat graduated from Glasgow in 1992 and pursued advanced training in internal medicine and cardiology in USA, becoming an ACVIM diplomate in 1998. After spells in first opinion and referral practice and a year at Sydney University he completed a PhD at Bristol, investigating mechanisms and novel treatments for autoimmunity. For the last 17 years he has worked at Davies Veterinary Specialists, UK, where he was Head of Internal Medicine and inaugural Clinical Director. He was awarded an RCVS Fellowship for Meritorious Contributions to Clinical Practice in 2018. His clinical interests include haematology and immunology, especially triggers for and management of autoimmunity. He regularly publishes and speaks nationally and internationally on these fields. He joined WSAVA Vaccination Guidelines Group in 2020. Outside work he enjoys photography, tennis, sailing and writing.