This study was undertaken as a result of the recommendations from the report “Research into cattle deaths and illness during sea” published in 1999 that identified the need for further investigation to determine the cause(s) of cattle deaths and illness during sea transport from Australia to the Middle East. This report further identifies factors that contribute to illness and death and makes recommendations to reduce morbidity and mortality of cattle during sea voyages. The study identified heat stress/ventilation and pneumonia from pasteurellosis as two major causes of illness and death and supported the findings of the previous report that a larger number of detailed necropsies to determine the cause(s) of cattle deaths during sea transport are essential.