In an adult cow with RDA showing metabolic alkalosis, hypochloremia, and hypokalemia, which intravenous fluids are indicated?

• A. Isotonic saline without potassium
• B. Saline fluids with KCl
• C. Dextrose solutions
• D. Lactated Ringer's solution

Answer: (B)

When a cow with an RDA presents with metabolic alkalosis and electrolyte losses, the goal of fluid therapy is to restore circulating volume while correcting the chloride and potassium deficits that are driving the alkalosis. Providing an intravenous fluid that adds chloride and potassium directly addresses these imbalances. Isotonic saline with potassium chloride supplies the missing chloride to reduce the alkalosis and supplies potassium to treat hypokalemia, helping to re-establish normal acid–base and electrolyte balance.

Fluids without potassium wouldn’t fix the potassium deficit and could perpetuate the alkalosis. Dextrose solutions don’t correct chloride or potassium and can cause insulin-driven shifts that lower serum potassium further. Lactated Ringer’s brings in lactate that is converted to bicarbonate, which can worsen metabolic alkalosis, and it contains only a limited amount of potassium.