Preliminary studies on lasalocid toxicosis in cattle

Polyether antibiotics are gaining widespread use in the feedlot cattle industry. One such investigational antibiotic, Lasalocid, was studied at oral doses of 25, 50, 75, 100 and 125 mg/kg to determine effects of toxicosis in six cattle. Deaths occurred at 100 and 125 mg/kg body weight. The general syndrome developed as muscle tremors, increased heart rate and respiration rate followed by or concurrent with anorexia (within 24 hr) and watery, forced diarrhea (48 through 72 hr). There were signs of cardiac effects one week to ten days after administration of the drug.