There is an Australian Accredited Veterinarian (AAV) on all long haul voyages with sheep to the middle east. These veterinarians will treat any sick animals and put them in hospital pens. If necessary, any sick sheep will be euthanised. If any sheep are found deceased in the pens they are moved to regular points for the AAV to inspect and perform a post mortem.
Post mortems are a normal part of disease investigation for a veterinarian. Knowing where the sheep was from on the deck and looking at its ear tag helps the veterinarian investigate the mortality and understand the cause of death and if there is any risk to other sheep.
Records of all sick and deceased sheep are entered into the daily report sent to the Australian Federal Government.
There is also an independent observer appointed by the Australian Federal Government on all voyages which provide another level of reporting to the federal authorities.