Arsenic poisoning has been an emerging problem in beef cattle. The poisoning usually occurs due to the ingestion of pesticides containing arsenic. However, Susan L. McClanahan, veterinarian at the University of Minnesota, has found a new source of arsenic that can cause sudden death in cattle. It has been found that ashes from burnt wood treated with the wood preservative copper-chrome-arsenate (CCA) have a high concentration of arsenic.

Many outdoor wooden structures are treated with this wood preservative and when this wood is burned, the resulting ashes will contain extremely toxic levels of arsenic. If these ashes are dumped in an area inhabited by cattle, the potential for sudden death due to arsenic poisoning becomes very real. Dr. McClanahan warns that burning structures in cow pastures or dumping ashes from wood treated with CCA is dangerous since cattle will die acutely after the ingestion of ashes. It is better to bury CCA treated wood and use new environmentally sensitive preservatives that do not contain arsenate when building new structures.