ECG alterations and changes in biochemical parameters associated with experimental salinomycin toxicosis in sheep

Salinomycin is a monocarboxylic polyether ionophore with antimicrobial properties. It is a dietaryadditive used as a growth promoter for ruminants and as a coccidiostat in chickens. The mechanism of actionof ionophores at the cellular level is to selectively bind certain ions creating intra and extracellularbiochemical disturbances. Clinical signs of ionophore intoxication are non specific and similar in all speciesand include tachycardia, muscle tremor, restlessness, loss of appetite, incoordination, muscular weakness and continual panting. The present study was conducted to determine the changes in ECG parameters andpossible arrhythmias and their types due to experimental salinomycin toxicosis in sheep. Acute toxicity withthe ionophore (0.5 mg/kg; intravenously) was induced in 6 mixed breed female sheep. A correspondingvolume of sterile saline was intravenously injected in each control sheep (n=6). Blood samples werecollected before and at various time intervals after the administration of either salinomycin or salinesolutions. Following centrifugation, serum biochemical parameters (ALT, AST, CK, LDH and total protein)were measured using conventional laboratory methods. In both groups, the heart sounds of sheep werecarefully monitored and the electrocardiogram (ECG) was recorded. Salinomycin caused a significant(P