Biochemical and pathological studies in chronic dichlorvos toxicity in buffalo calves.

摘要

Five buffalo calves (8-12 months old, 65-135 kg) were drenched with dichlorvos (Nuvan 76%; 0.125 mg/kg) daily for 91 days. Five calves were kept as untreated controls. Blood samples collected at intervals on the day of dosing and during the 91 dayswere used to measure plasma cholinesterase, aminotransferases, alkaline phosphatase, glucose, cholesterol, urea nitrogen, total proteins and immunoglobulins. The calves were weighed fortnightly and killed on day 92 and examined PM. The dosed calves did not develop any significant signs of toxicity or show loss of body weight. Diarrhoea occurred occasionally after 35 days of dosing. Cholinesterase was significantly inhibited from day 3 of dosing with maximum inhibition on day 49 followed by a gradual recovery which did not reach normal by the end of the trial. Aminotransferases increased gradually until day 49, aspartate aminotransferase reached a maximum on day 77. These enzymes then decreased slowly to reach near normal at the end of the study. Grossly, dosed calves showed varying degrees of gelatinization of subcutaneous adipose tissue. Livers showed mottling with fibrous deposits on the surface. Cut surfaces were pale and anaemic. Intestinal mucosa was congested and lumina contained abundant mucinous fluid. There was severe pulmonary congestion and emphysema, sub-endocardial haemorrhages and leptomeningeal congestion. Severe microscopic lesions were found in the brain, liver, lungs, heart, kidneys, abomasum, intestines and testes.