Loris attended St. Paul's School between 1893 and 1898. He then entered St Bartholomews Hospital as a student in 1898, and obtained the diplomas of M.R.C.S (Eng.), L.R.C.P. (Lond.) in 1904. After that Loris went to India, where he was appointed District Surgeon under the Great Indian Peninsula Railway Company.
The India Army Quarterly List for January 1912, lists Loris on page 589a as Surgeon-Captain, date assigned 1 April 1910: Staff Unit G.I.P.R. (i.e., Great Indian Peninsula Railway) Volunteer Rifle Corps. He was a medical Officer with the railway and stationed at Igatpuri at the time.
In 1915 he obtained a commission in the R.A.M.C. and attained the rank of Capt. Just before his death he was attending plague cases in the Bhusvaal District and infected himself with plague while performing a post-mortem examination; from this he died. He was buried the following day in Sewri Cemetery, Bombay on 19th December 1916.
He was survived by his widow Gertrude Malleson Arnould née Fearon whom he had married on 6 November 1908 in Bombay and their three children, Ann Fearon Arnould (born 1909), Joan Veronica Arnould (born 1914) and Pamela Loris Arnould (born posthumously 1917). Loris was the youngest son of Alfred Henry Arnould, solicitor, and Clara Elizabeth Arnould of 9 Nevern Square, SW3. (Information sources: Saint Bartholomews Roll of Honour and Loris's family)