Dabormida was the son of Count Giuseppe Dabormida, an artillery colonel, Minister of War of the Kingdom of Sardinia during the First Italian War of Independence and Foreign Minister in the first Cavour government. He was admitted in the Royal Military Academy in 1859, and graduated in December 1861 as an artillery sub-lieutenant. In March 1862 was attached to the Artillery Staff, then, a year later, assigned to the 5th Artillery Regiment. On 31 December 1863 was promoted to lieutenant. During the 1866 Italo-Austrian War he commanded a supply column, and by December was moved to the Army Staff. A year later he entered the newly founded School of War for a two-year specialization course. Promoted captain in 1868, in 1870 he started teaching courses of Military History in the same institution.