RESUMO
Dried leaves of oleander were orally given at a single dose of 500 mg/kg body weight to 20 clinically healthy male chickens. Clinical signs of toxicosis began to appear about 1 h after receiving the oleander and included hypersalivation, vomiting, diarrhea, deep depression, and sudden death. Also, hyperemia in the combs and wattles was obviously seen. Electrocardiograms (ECG) were repeatedly recorded at 30 min intervals. ECGs findings included increasing the QRS duration in some birds and various kinds of arrhythmias. Bradycardia was the most frequently detected finding (30.43%). During necropsy, there were congestion and hemorrhages in the visceral organs particularly in heart, liver, kidney, and lung. Histopathology revealed myocardial cell necrosis with hyperemia and hemorrhage, severe diffuse pulmonary congestion and edema, severe renal congestion and hemorrhage with tubular necrosis, and coagulative necrosis of hepatocytes with hyperemia and hemorrhage. There were also congestion, mild epithelial necrosis and desquamation with infiltration of mononuclear inflammatory cells in the proventriculus of all birds. There was also mild to moderate congestion in the intestines with scattered necrosis of surface enterocytes. The lack of information about the toxicity of oleanders in poultry was the main cause for this study. The results suggest that chickens appear to respond to oleander poisoning in a manner similar to other species.
