Furosemide is injected either intramuscularly or intravenously , usually - mg/kg twice/day, although less before a horse is raced. As with many diuretics, it can cause dehydration and electrolyte imbalance , including loss of potassium , calcium , sodium , and magnesium . Excessive use of furosemide will most likely lead to a metabolic alkalosis due to hypochloremia and hypokalemia . The drug should, therefore, not be used in horses that are dehydrated or experiencing kidney failure. It should be used with caution in horses with liver problems or electrolyte abnormalities. Overdose may lead to dehydration, change in drinking patterns and urination, seizures, gastrointestinal problems, kidney damage, lethargy, collapse, and coma.