LEAD-POISONING AND TOXICOKINETICS IN A HEIFER AND FETUS TREATED WITH CANA2 EDTA AND THIAMINE

Lead (Pb) poisoning of a pregnant heifer was diagnosed based upon clin ical signs (head pressing, blindness, muscle twitching) and a blood le ad concentration of 1.73 ppm. Blood and urinary Pb half-lives with CaN a2 EDTA/thiamine therapy were determined to be 2.08 and 1.38 days, res pectively. Many cations (Ca, Fe, Zn, Na, Cu), including Pb, were excre ted at higher concentrations in urine during therapy. Blood (0.425 ppm ) and liver (4.85 ppm) Pb concentrations in the fetus were 71.7% and 8 4.3% of the same tissue Pb concentrations of the dam, indicating a sig nificant transfer of Pb in utero. Severe polioencephalomalacia was des cribed in the adult, and hepatic lysosomes with metallic electron dens ities were present in the fetus.