Acute 2,4-dichlorophenoxyacetic acid intoxication in cattle

The acute toxicity of 2,4-dichlorophenoxyacetic acid (2,4-D) was studied in cattle. Steers were orally treated with 100, 300 or 600 mg 2,4-D/kg. Behavioral alterations, heart and respiratory functions, rectal temperature and ruminal movements were observed at 2, 4, 8, 12, 24, 48, 72 and 96 h after treatment. At these moments, blood and urine samples were collected and serum 2,4-D levels were determined. Results show that animals' vital function and hematocrit were not modified by the herbicide. Other signs were doses and time-dependent and included motor alterations (weakness, lethargy, decreased general activity) and decreased ruminal movements and proteinuria. The herbicide was rapidly excreted and the intoxication signs were completely reserved. 2,4-D is an herbicide of small toxicological consequences for cattle kept under in natural grazing systems.