Physiopathological effects of the administration of chronic cyanide to growing goats - a model for ingestion of cyanogenic plants

Ingestion of cyanogenic plants, such as cassava and sorghum, has been assoc iated with goitre and tropical pancreatic diabetes in both humans and anima ls. Thus, the objective of the present study was to determine the toxic eff ects on the thyroid and pancreas in growing goats of prolonged exposure to potassium cyanide (KCN). Thirty-four male goats were divided into five grou ps dosed with KCN at 0 (control), 0.3, 0.6, 1.2 or 3.0 mg/kg daily for 5 mo nths. Blood samples were obtained in order to determine the glucose, choles terol, thyroxine (T-4), triiodothyronine (T-3) and thiocyanate concentratio ns and for haematological studies; pancreas and thyroid gland were collecte d for histopathological study. The group receiving the highest dose of cyan ide showed lower body weight gains and carcase weights and a decrease in pl asma T-3 concentrations compared to the control group. Reabsorption vacuole s in follicular colloid and normocytic normochromic anaemia were observed i n the experimental animals. Inhibition of peripheral conversion of T-4 to T -3 is suggested. However, no diabetogenic effects were observed.