Lieutenant Colonel Peter John McQuaid qualified MD from Queen's University of Ireland in August 1872. He entered the Army Medical Department as a surgeon in 1873.
He served in the Afghan war 1878–1879, and was present in the engagement at Charasiah on 6 October 1879,
and in the operations round Kabul in December 1879, including the actions of Karez Mia and Aowshar and the subsequent defence of the Sherpur Cantonments. (medal with two clasps). He was also in the Egyptian war of 1882, and was present at Kassasin on 9 September and at the battle of Tel-el-Kebir (medal with clasp, and Khedive's bronze star).
Lieutenant Colonel Peter John McQuaid retired from the service on 9 August 1896.
Service Record — Peter John McQuaid
30 Sept 1873 Commissioned Surgeon.
1874 – 1880 Served in Bengal.
1878 – 1880 Served in the Afghan War. Was praised for his services during the Afghan Campaign.
Dec 1880 Returned to Netley.
1881 – 1882 On duty at the Royal Victoria Hospital, Netley.
Apr 1882 Moved to York.
July 1882 Served in the Egyptian Expedition. Was at Kassassin on 9 September and the Battle of Tel-el-Kebir.
Malta 5 Mar 1885 Arrived from Colchester.
Malta 30 Sept 1885 Promoted Surgeon–Major after twelve years full pay service.
Malta 1886 On garrison duty.
Malta 1887 On garrison duty.
Malta 3 May 1888 Resident at Strada Spinola St Julians. To England on leave.
Malta 2 Aug 1888 Returned from leave.
Malta 1889 On garrison duty.
Malta 1890 On garrison duty.
Malta 7 Feb 1891 Left for Portsmouth, England.
Aug 1891 Moved from Portsmouth to Parkhurst.
30 Sept 1893 Promoted Surgeon-Lieutenant Colonel after twenty years on full pay service.
19 Aug 1896 Placed on the retired list.
July 1901 Brought back on the establishment from the Army Medical Reserve and placed in medical charge of troops at Portsmouth.
18 Oct 1902 Re-employed at Portsmouth. Promoted to colonel on the retired list in recognition of his services during the operations in South Africa.
Apr 1903 Ceased to hold medical charge of troops at Portsmouth.
10 Dec 1909 Died at 6 Vyne Road, Basingstoke.