Cattle deaths across Victoria have been traced to burn piles containing CCA-treated pine fence posts, with farmers undertaking post-bushfire clean-up inadvertently exposing their stock to concentrated arsenic. That is according to Agriculture Victoria, which issued the warning after a disease investigation near Wangaratta confirmed multiple cattle deaths on a property where treated timber had recently been burnt.
Agriculture Victoria veterinary officer Dr Lydia Nicholson said the Wangaratta case served as a sobering reminder that well-intentioned post-fire property management can deliver fatal consequences for livestock. “During a disease investigation, several cattle were found dead after displaying severe neurological signs — staggering, blindness, and collapse,” Dr Nicholson said, explaining the key breakthrough came when a discussion with the landholder revealed a bonfire on the property had included treated timber.
Treated pine is one of the most common materials used in Australian agricultural fencing, yards, and landscaping, preserved with copper-chrome-arsenate (CCA) to protect against rot and pests. Burning concentrates the arsenic present in CCA into residual ash and debris that proves both palatable and lethal — a chemical transformation Dr Nicholson said many landholders are unaware of when clearing fire-damaged infrastructure from their properties.
Agriculture Victoria also identified garden clippings as a parallel hazard, with dried plant material commonly becoming more palatable to animals whilst retaining its full toxicity. Oleander, yew, foxglove and rhododendrons can cause sudden death through damage to the heart, nervous system or gastrointestinal tract — a risk the agency said recently led to multiple horse fatalities on a Victorian property where oleander clippings had been placed on a burn pile.
The warning carries particular weight across Victoria’s northeast, where fire restrictions have recently lifted and burn operations are now underway on properties undertaking fence replacement after the recent bushfire season. As Wood Central reported in its coverage of the Australian Timber Circularity Project, CCA-treated post disposal — with an estimated 27 million posts already stockpiled on vineyards alone — remains one of the most pressing end-of-life challenges facing the domestic timber supply chain.
Landholders are urged to contact their local veterinarian or Agriculture Victoria animal health officer before burning any timber materials, with further information available at agriculture.vic.gov.au/livestock-and-animals. “In this case, every animal that had access to the burn site died,” Dr Nicholson said, confirming a 100 per cent mortality rate among cattle at the Wangaratta property.
