I was struck by a report (and here) that there had been an anthrax outbreak in the Upper Hunter, killing a number of cattle. I did not know that anthrax is a relatively common occurrence, with an anthrax belt from Victoria along the Western Slope to about Moree.
The outbreak in the Upper Hunter is unusual since this is not a known anthrax area, with the last reported outbreak in the 1940s. However, anthrax can survive dormant in soil for very long periods.
In the latest case, it seems possible that the recent drought breaking rains exposed the bacteria.