MB ChB Manch 1911.
Before the First World War, Cowan was working in general practice. After joining the RAMC, Cowan was severely wounded and unable to return to his practice. As a result, he took up massage and electrotherapy and was appointed medical officer in charge of the Massage and Electrotherapeutic Department at Eastbourne Convalescent Military Hospital. Cowan carried on in this area of work until he was demobilised in 1919. He then moved to Manchester where he held the position of honorary physician in charge of the Physiotherapeutic Department at Ashton-under-Lyne Infirmary and also physiotherapeutist at Grangethorpe Hospital, Manchester and at the Orthopaedic Clinic of the Ministry of Pensions in Deansgate. From 1921 until 1957 Cowan held the position of consultant physician at MRI, Manchester Northern and Jewish Hospitals and Macclesfield Infirmary. His son John Robert Cowan, a medical student at Manchester, went missing during the Second World War. Cowan was a member of Manchester Medical Society , the Royal Society of Medicine and the British Association of Physical Medicine.