His personal best throw was 82.60 achieve in oristano Italy June 1991 Edinburgh.[1]
At a meet in Palio della Quercia, Italy on 24 July 1994, Mackenzie failed a doping test, having taken dextropropoxyphene. The medication was for an ankle injury that would also bar him from competing at the 1994 Commonwealth Games in August. In September, the failed test was revealed. Mackenzie claimed his innocence, and that the medication was not performance-enhancing, but rather had the adverse effect.[3] Nonetheless, Mackenzie received a doping ban for three months, the same as his fellow countryman Solomon Wariso.[4]