Educated at Glasgow, where he took the MB and CM with commendation in 1884.
5 Feb 1887 Commissioned Surgeon-Captain.
5 Feb 1899 Promoted Major RAMC.
1900 Served in the Third China War when he was mentioned in dispatches in the London Gazette of 13 September 1901.
1 May 1902–25 Apr 1906 Deputy Assistant Director General Army Medical Services.
Malta 7 Apr 1906 Embarked for Malta with Col David Bruce as a new member of the Mediterranean Fever Commission.
While in Malta, Major McCulloch was admitted to Cottonera Hospital with phlebitis of his leg. He returned to England on 26 Sept 1906 on the Postal and Oriental Steamer Caledonia.
Malta 7 June 1907 Was highly commended by the Royal Society for services rendered in connection with the investigations into the causes of Mediterranean Fever.
29 July 1911 Promoted Lieutenant Colonel RAMC vice Sir Joseph Fayrer Bart. who retired.
28 July 1914 Start of the Great War.
4 Aug 1914 Britain declares war on Germany.
1914 Re-employed during the Great War.
2 May 1915 Lieutenant Robert Arthur Douglas McCulloch, 1st Battalion The King's Own, Royal Lancaster Regiment, dearly loved elder son of Lieutenant-Colonel T McCulloch RAMC, of 6 St. George's Road, Bedford, was killed in action, near Ypres, aged 19.
25 June 1915 Died suddenly of heart disease at the Queen Alexandra Hospital, Cosham, Portsmouth, aged 54 years.