I'm currently researching my Keane ancestors and have hit a brick wall that I'm hoping someone can help me with. Thomas Francis Keane (father Thomas Francis Keane, as were his son and grandson

) was born in Athlone, Westmeath, Ireland in 1858, according to several sources including his Service Attestation and obituary. His obituary says he "was born in the East Lancashire Regiment or rather the 59th Notts which afterwards became the 2nd East Lancashires... As a small boy, before enlisting, Mr Keane was in Mesopotamia, Africa, and Egypt with his father and mother whilst his father was serving."
I've done searches on Ancestry and FMP but can't find any trace of his birth. were 'military' births recorded seperately? I've searched the (digitised original) parish birth records for St Mary's Athlone, but found no trace. His earliest Regimental number was 1549, later 461, then 6940.
This family is proving to be a tough nut to crack given their lack of imagination with names and professions - Thomas, his father, and his son all served with the East Lancs!
Any pointers would be greatfully received.