After his graduation he spent two years studying obstetrics and gynaecology at Paris and at Freiburg, Germany.
During World War I Hendry served as a Major in Royal Army Medical Corps in France.
In 1943 he succeeded Samuel James Cameron as Regius Professor of Midwifery at Glasgow.
He became ill shortly after his election but carried on with his duties until he died of lung cancer in 1945.
Peel, John (1976) The Lives of the Fellows of the Royal College of Obstetricians and Gynaecologists: 1929-1969, London, Heinemann Medical Books