Burn-pile leads to arsenic poisoning
By Cat Barr, PhD
Fifteen crossbred calves were placed in a pasture with a burn-pile. The day after they were provided with Johnson grass hay, one calf was found dead. Two days later, three calves were walking abnormally and had diarrhea. Feces from those calves was submitted to the Texas A&M Veterinary Medical Diagnostic Laboratory (TVMDL) for testing. Fecal parasite exams yielded negative results. Blood drawn from two other heifers, also submitted to TVMDL for testing, contained 1.20 and 0.81 ppm arsenic. Blood arsenic levels over 0.17 ppm indicate acute arsenic poisoning. Assuming the source was the burn-pile, the arsenic could have come from treated lumber or from old pesticide formulations that were thought to have been destroyed by fire.
Since the 1940s, many outdoor structures have been built using pressure-treated lumber, processed with chromated copper arsenate (CCA). CCA-treated lumber was banned from residential use in 2003, but existing structures were deemed not to cause unreasonable risk to the public. CCA-treated lumber is still used for commercial, industrial, and some agricultural purposes. Producers should be aware that for disposal purposes, burning old structures made with CCA-treated wood is not sufficient to get rid of the arsenic. Additional disposal methods, such as burying the ashes, may be helpful in preventing livestock poisonings.
Discarded automotive batteries and their lead battery plates may be additional sources of livestock poisonings. Even though their casings may have been destroyed by fire, lead battery plates still have the potential to poison livestock. For example, calves will find and chew on lead battery plates, resulting in lead poisoning. A calf that appears blind, or has an ear twitch, starts head-pressing or becomes aggressive could be lead poisoned. Whole blood (EDTA) is the best sample to submit for diagnostic testing.
To learn more about this case, contact Dr. Cat Barr, Veterinary Toxicologist at the College Station laboratory. For more information about TVMDL’s test catalog and services, visit tvmdl.tamu.edu or call 1.888.646.5623.