Commodity analysts at Mecardo say millions of the 8.6 million sheep and 2.3m cattle in the two states are likely.
They account for 12% of Australian sheep and 9% of cattle.
Mecardo analyst Matt Dalgleish said it is difficult to determine exact numbers. Losses have been calculated at an average of 20%.
Should these figures prove to be borne out Australia stands to lose 1.7 million head of sheep and 450,000 cattle.
“We have managed to map the six key areas in NSW and Victoria that have been significantly impacted since early December. There are parts that are still burning so those losses may continue to increase yet.”
The calculations are for four pastoral zones in NSW and two in Victoria. The Northern Tablelands in NSW has the highest number of stock with almost 700,000 cattle.
If the calculated losses are borne out the fires could wipe out 2.5% of the country’s sheep and almost 2% of cattle.
“This comes in a year that was already going to be tight for livestock numbers. Farmers have been running down flocks and herds for the past year due to the drought and we were already forecasting it would be a scramble to restock anyway.
“We may have lost 2% and we are not even halfway through the fire season yet.”
Farmers and vets expect even without any further immediate fire losses the toll will mount in coming weeks as livestock succumb to the effects of heat, burns and smoke inhalation.
There is also an enormous animal welfare issue arising as farmers with burnt pastures and fences and no operable water supplies struggle to keep surviving stock alive.
In Victoria field teams are assessing properties to address animal welfare issues, including euthanasing stock.
Dalgleish said climate predictions made for the country a decade ago have proved to be spot on.
“My concern is if we are at the beginning of a new climate cycle in Australia. We used to have a 20-year time span of four to five years of wet, some dry and then normal in between. It gave farmers time to restock.
“If that dynamic is shifting, with 13 years of drought, you don’t have time to restock with cattle in particular.”