If you look up the lethal dose for potassium chloride on a page like this, the oral value is 2,600 mg per kilogram. If you weigh 75 kilograms (165 pounds), you would need to consume 75 * 2,600 = 195,000 mg of potassium to reach fatal levels. That's 487 bananas worth.I'm not so sure about chickens, but I work with a dietitian who used to work at a kidney dialysis center. She told me that patients who didn't want to deal with their renal disease anymore would load up on potassium and kill themselves. Suicide by potato chip.
Imp