The keeper I spoke to looked after them directly in quarantine before they reached Australian soil!I had a look and according to Flight of the Rhino (1993), there were three male black rhinoceros deaths:
Kalungwizi (the first female to give birth to a calf at Dubbo), was captured along with her unnamed infant male calf in 1992. The calf died prior to export of a twisted intestine.
Tamana (an adult bull) died on Day 42 of the 60 day quarantine at Cocos Island of Haemolytic anaemia.
A young bull named Chamupupuri died at Dubbo from severe head injuries caused by running into a fence.