Oh sorry, RHD is Rabbit Haemorrhagic Disease, once known as Rabbit Calicivirus Disease (RCD). It was first introduced to Australia in the late 1990s, and new strains have been occasionally released subsequently.
Hi @AlisonMilton, rabbits that die from RHD typically do so suddenly, without a lengthy period of feeling unwell, and some don't even make it back to a burrow (like almost all other kinds of sick rabbits mostly do). So you can find carcasses that look like this. Scavengers respond very quickly, so the presence of perfect-looking carcasses like this usually only applies for the first day of an RHD episode. At this stage of decomposition they are not unpleasant to necropsy. Just slit the abdomen and look for blotches or haemorrhaging on the liver, kidneys, or maybe even the heart. If present, in an animal looking like this, RHD.